This is a list of acronyms, expressions, euphemisms, jargon, military slang, and sayings in common or formerly common use in the United States Marine Corps. Many of the words or phrases have varying levels of acceptance among different units or communities, and some also have varying levels of appropriateness (usually dependent on how senior the user is in rank). Many terms also have equivalents among other service branches that are not acceptable amongst Marines, but are comparable in meaning. Many acronyms and terms have come into common use from voice procedure use over communication channels, translated into the phonetic alphabet, or both. Many are or derive from nautical terms and other naval terminology. Most vehicles and aircraft have a formal acronym and/or an informal nickname, those are detailed in their own articles.
The scope of this list is to include words and phrases that are unique to or predominantly used by the Marine Corps or the United States Naval Service. For other military slang lists, see the "See also" section.
360 – complete circle on a compass (360°); to put protection all around.
48, 72, 96 – in hours the standard liberty periods of two, three, four days.
4th Battalion – pejorative used to describe an individual or unit lacking toughness as in "He was trained in 4th Battalion". Derived from the 4th Battalion of the Recruit Training Regiment at MCRD Parris Island which trains female enlisted Marines.
4th Marine Dimension – a derogatory term for the 4th Marine Division, the division to which the ground combat element of the Marine Forces Reserve is assigned; used by active duty Marines to denote displeasure with the difference in culture and operating procedures within the division as opposed to active duty units.
5.56mm hickey – a scar or blister resulting from a burn suffered (usually on the neck) due to hot brass.
7 Day Store – Convenience store.
782 gear or deuce gear – standard issue web gear, combat gear, or field equipment, such as ALICE, MOLLE, or ILBE. Named after standard Marine Corps Form 782, which Marines formerly signed when they took custody of and responsibility for their equipment.
8 bells – signal for the end of a four-hour watch, so named for the increase in bell strikes by two at each hour of the watch.
above my/your pay grade – expression denying responsibility or authority (indicating that the issue should be brought to higher-ranking officials); alternatively, a semi-sarcastic way of telling someone that they're not authorized to receive certain information.
acquire – euphemism denoting theft, sometimes jokingly referred to as "tactical"
VMX – Marine Tiltrotor Operational Test and Evaluation Squadron
ZMQ – Marine Barrage Balloon Squadrons
aye-aye or aye – nautical term used as a response to orders meaning "I understand the orders I have received and will carry them out"; aye (descended from Middle English yai) dialectical for 'yes', once common in the regions from which the Royal Navy drew its sailors
BAMCIS – a mnemonic for military tacticians: Begin the planning, Arrange reconnaissance, Make reconnaissance, Complete the planning, Issue orders, Supervise. It is also used as an exclamation of success or accomplishment.
'Barney-style – to perform strictly according to regulation; idiot proof; simplified for the benefit of mental underachievers; also called "Breaking it down Purple Dinosaur-style"; Burt and Ernie for the 80's and 90's Marines
battle zero or battle sight zero or BZO – calibrated settings on a gunsight which contribute to accuracy; used as default before adjusting windage or elevation; also used as verb when triangulating a BZO.
boondoggle – project or trip on government time and/or expense which serves no purpose other than to entertain the person making it.
boot – A term for Marines who are new to the Marine Corps. Derived from the term "boot camp", to insinuate that the Marine is fresh out of boot camp. Generally used as a pejorative term (even if in an affectionate manner) in the Fleet and elsewhere, sometimes as a way to explain that new Marines should know their place. It can also be used as a term for a Marine who is new to a rank or billet. e.g. - "He's a boot Corporal". Meaning, said Marine was just recently promoted to Corporal. See also: Shower shoe
"By your leave sir/ma'am." – used with a salute when passing senior officers who might be advancing in the same direction; some protocols say the senior must give clearance before the junior can pass.
Captain's Mast – office hours afloat. The term "Captain's Mast" is almost universally negative, implying non-judicial punishment. The modern Navy and Marine Corps use the term "Meritorious Mast" to announce any ceremony involving the meritorious award of a higher rank or of a particular recognition or honor.
carry on – order to continue after being interrupted.
CAS – Close Air Support, aircraft fire on ground troops in support of nearby friendly troops.
CASEVAC – CASualty EVACuation, emergency evacuation of injured personnel from combat zone by any modes of transport available, as opposed to a MEDEVAC carried out by ambulance equipment designed solely for the purpose. See also MEDEVAC.
Casual Company or CasCo – a holding unit/formation of Marines awaiting one of the following: discharge from the Corps, training (usually at a formal school), or deployment to a unit.
CCU – Correctional Custody Unit, a hard-labor and heavy discipline unit overseen by MPs or Navy Masters-at-Arms to which Marines and Sailors found guilty of minor UCMJ offenses through NJP are sent for up to 30 days in lieu of confinement in the brig.
Chinese field day – a form of field day where every item from a room is removed for cleaning; when tending to last much longer than necessary, it is used as a punishment, typically for unsatisfactory performance in routine field day.[unreliable source?][unreliable source?]
chit – voucher, receipt, letter, or note, entitling the bearer to special treatment, such as medical restrictions from duty; derived from Hindi word for "letter", "chitti".
CIF – Consolidated Issue Facility, a place on a station where all personal equipment is stored and issued, often contracted to civilians.
CID – Criminal Investigation Division, is an accredited Federal law enforcement agency of the U.S. Marine Corps whose mission it is to conduct official criminal investigations into misdemeanor and felony offenses committed on Marine Corps installations as may directed and not under the primary jurisdiction of the Naval Criminal Investigative Service (NCIS). Accredited Marine Corps CID agents may be assigned to NCIS as special agents in accordance with a memorandum of understanding.
COC – Combat Operations Center, the command post for a combat arms unit, usually of battalion-size or larger; personnel assigned to the COC may derisively refer to such duty as "coc-watch" or "working the coc".
deep six – to dispose of by throwing overboard ship.
detachment – a portion of a unit sent independently of its parent organization, usually in support of a larger headquarters; or a small stand alone unit isolated geographically from its parent command.
deuce – reference to the number two in various unit or equipment names; the senior intelligence officer for a unit;
deuce gear – see 782 gear, from the last digit in that term.
diddy bop – poor performance in close order drill, or marching in a manner that does not present a crisp military appearance. One who conducts himself/herself in this manner is labelled a diddy bopper.
Diet Private or Diet Tray – A recruit in Boot Camp who has been deemed overweight according to regulations. These recruits are usually the last through the chow line and have their meals inspected by DI's.
digis or diggis – digital camouflage such as MARPAT; also refers to the digital-patterned MCCUU.
dog – small metal fitting used to secure watertight doors, hatches, covers, scuttles, etc.; also, to close/secure such door/hatch; also, slang for Marine, from the term Devil Dog.
dog and pony show – any display, demonstration, or appearance by Marines at the request of seniors for the pleasure of someone else, such as a ceremony or parade; also, pejorative for the requirement for over-perfection of such a venue.
donkey dick – Specifically, a jerrycan fuel spout. Alternatively, slang for virtually any piece of equipment which has a generally cylindrical or phallic shape with unknown, or obscure official name. For example, a static hook suspended from an overhead helicopter for the purpose of picking up external loads.
dope – information, or sight settings and/or wind corrections for a rifle under given conditions, possibly from aircraft dope.
downrange or down-range – dangerous area, from the portion of a shooting range that receives impacts; also the execution of a plan.
drill – close order drill, the procedures and methodology of handling weapons and moving troops about in an orderly fashion, used to indoctrinate recruits in obedience to commands and military appearance.
drill hat – a Drill Instructor, usually the second in command to the SDI who specializes in instruction in drill. Not to be confused with kill hat.
field hat – campaign cover, a broad-brimmed felt hat, originally with one straight crease down the middle, then with a Montana peak, worn on expeditionary missions from 1912 to 1942, and then again authorized in 1961 for wear at recruit depots by drill instructors and rifle ranges by marksmanship instructors. See also campaign cover, hat, & smokey bear/brown.
field meet – organized sporting competition, often involving athletics and/or soldierly skills.
field music – drummer, trumpeter, bugler, fifer; mostly an antiquated term.
field-strip – to disassemble a piece of ordnance or weapon to the major part groups for routine cleaning or lubricating; to strip cigarette butts to their filters before throwing away. Also to remove unwanted items from an MRE in order to save space.
gun club – slang term for the USMC at-large as in "I've been in this gun club longer than you." Use in presence of senior personnel is inappropriate. Use by civilians or members of other services is considered disrespectful.
HEDP – High-Explosive Dual Purpose, type of armor piercing ammunition.
high and right – losing one's temper or rationality; from the common error of a poor shooter to jerk the trigger and impact the upper right side of a target.
high and tight – nickname for a common variant of the buzz cut, where the hair is clipped very close. Although having become heavily associated with Marines (giving rise to the term "jarhead"), it's generally not the most common or preferred haircut worn amongst most Fleet Marines.
high-speed – new, interesting, or cool; often used to sarcastically denote that the subject looks good, but performance is dubious.
hooch or hootch – tent, hut, or otherwise temporary or ramshackle dwelling. Also tied into the term Hooch maid, which referred to a woman in Vietnam who would clean the dwellings of soldiers, which were deemed "hooches."
Hot-Shit – sarcastic reference to an overly arrogant person.
horse-cock sandwich – any sandwich or meal created using an unknown or mystery meat. Often, specifically, sliced balogna. Occasionally served as breakfast meat.
house mouse – recruit tasked with cleaning and performing domestic chores in drill instructor-only areas. See also DI hut.
hurry up and wait – expression denoting inefficient time management or planning, often when a senior rushes a unit into a situation too fast that subsequently makes them wait.
huss – to give a helping hand, so named because the H-34 Choctaw helicopter's utility configuration was designated as the "HUS-1 Seahorse," leading to Vietnam-era Marines that needed a medical evacuation helicopter to ask for or to be "cut a huss".
in country – phrase referring to being within a war zone.
incentive/individual training or IT – physical training used as a punishment, especially in recruit training, sometimes nicknamed "incentive torture," "indoor tennis," or getting "thrashed/bent/slayed/destroyed" by recruits. See also pitting & quarterdecking.
jarhead – pejorative term for a Marine. Jarhead has several supposed origins: the regulation "High and Tight" haircut resembles a mason jar (to add insult, some note that the jar is an empty vessel, also therefore a Marine's head an empty vessel); the Mason Jar Company stopped making jars and made the helmets for Marines during World War II.
Jesus slippers or Jesus boots – government-issue sandals or flip-flops for sanitation in showers. See also shower shoes.
Joker – military journalist, from Private Joker from the movie Full Metal Jacket; also a derogatory term for a junior enlisted servicemember. Also, used by aviators, the time at which only 60 minutes of fuel remain.
JTF – Joint Task Force, a provisional unit or formation from more than one branch of service.
Lance Coolie, Lance Criminal, or Lance Coconut – derogatory terms for Lance Corporal.
Lance Corporal Underground or Lance Corporal Network – joking reference to the gulf between non-NCOs and their superiors; also refers to the spread of foolish rumors that a more experienced Marine would immediately recognize as false.
leatherneck – nickname for Marine, so named for legends stating that stiff leather collars were once worn to protect the throat from sword-blows (also thought that high stocks were worn for discipline, to keep Marines' heads high and straight). The dress blue uniform still bears a high stock collar today. Also, Leatherneck Magazine.
Major – a Captain in command of a ship's Marine detachment, so titled because a ship may have only one Captain, the commanding officer.
Mama-san – term of endearment for an elder Japanese woman, often a maid, cook, or tailor/seamstress performing services for Marines; from the Japanese honorific suffix "san".
MARINE – Muscles Are Required, Intelligence Non-Essential or My Ass Rides In Navy Equipment, pejorative backronyms used by other branches.
Marine – the following nicknames are usually acceptable: leatherneck, devil dog, sea soldier, warrior, hard charger, motivator; the following are acceptable from other Marines: jarhead, gyrene; the following are grievous insults: soldier, seabag.
military left – pertaining to the left side of something or the direction to the left of the subject in question. Used sarcastically when giving orders when a subordinate turns the wrong way or is unsure of which way to turn.
military time – the time of day on a 24-hour clock. General Wallace M. Greene forbade the practice of suffixing the unnecessary word "hours" after each indication of time of day ("1330" or "thirteen-thirty" instead of "1330 hours"); the practice of saying "oh" instead of "zero" for hours before 1000 has diminished as well.
MRE – Meal, Ready-to-Eat, standard U.S. field ration. Sometimes jokingly referred to with backronyms such as "Meals Rejected by the Enemy," "Meals Rejected by Ethiopia," "Meal, Rotten to Eject," "Meals Rarely Eaten," "Meal, Reluctant to Exit," "Mister E," or the "Three Lies for the Price of One".
MRE bomb – bursting plastic bag made from chemical heating pouches found inside of a standard MRE.
NCOIC – Non-Commissioned Officer In Charge, an NCO responsible for a group of Marines, but without the authority of a commissioned officer; somes also the senior enlisted Marine acting with the officer in charge. See also OIC & SNCOIC.
O-dark thirty – very early hours before dawn. See also military time. The custom of saying "oh" instead of zero has diminished, but remains in this expression.
office hours – administrative ceremony where legal, disciplinary, and other matters (such as praise, special requests, etc.) are attended, designed to dramatize praise and admonition, in a dignified, disciplined manner, out of the ordinary routine. Known as Captain's Mast afloat. An award given during a positive office hours or Mast is known as a Meritorious Mast, a negative office hours with punishment awarded is an example of non-judicial punishment.
officers' country – living spaces for officers aboard ship, or portion of post or station allocated for the exclusive use of officers.
OFP - Own Fucking Program. When a marine does what he wants to, when he wants to and gets away with it.
old Asia hand – person with more than one tour in Asia.
Old Man – very informal nickname for the commanding officer, considered an inappropriate term of endearment for use by a junior, thus used in reference but never in address.
OMPF – Official Military Personnel File, a record of all awards, punishments, training, and other records compiled by Headquarters Marine Corps.
oorah or ooh rah or Urah – spirited cry used since the mid-20th century, comparable to Hooah used in the Army or Hooyah by Navy SEALs; most commonly used to respond to a verbal greeting or as an expression of enthusiasm. The origin is often disputed.
OOB – Out Of Bounds, or straying into an area restricted from use by normal traffic, prohibited to Marines, or too far from base for a given liberty period.
OOD – Officer Of the Deck, or the senior Marine responsible for the patrol and security of a unit's garrison working spaces and sleeping quarters after working hours, usually responsible for subordinate sentries and acts as a guard commander. See also duty & firewatch
Oscar Mike – On the Move, the names of the two NATO phonetic alphabet letters O and M which stand for the phrase. Used on the radio and in shorthand to each other. See also NATO phonetic alphabet
Page 11 – NAVMC 118(11), a page of a Marine's Service Record Book or Officer Qualification Record where administrative remarks are made concerning a Marine's performance and conduct, and which may contain negative recommendations regarding promotion or re-enlistment; while not a punishment itself or inherently negative, it is part of a Marine's permanent service record and used as a basis for administrative decisions regarding a Marine's career; the term commonly refers to an entry itself made in this section.
parade ground/field/deck – area set aside for the conduct of parades, drill, and ceremonies, often paved or well-maintained lawn. See also grinder.
passed over – having failed selection for the next higher rank (for SNCOs and officers).
pay grade – DOD system of designating a U.S. serviceperson's pay (E-1 through E-9, W-1 through W-5, and O-1 through O-10), not to be confused with rank (though the two usually correspond) or billet.
PCP – Physical Conditioning Program, exercise regimen for Marines failing to meet the minimum physical requirements; also Physical Conditioning Platoon, for the unit where a physically unfit recruit is sent prior to recruit training, nicknamed Pork Chop Platoon.
pizza stain – a nickname used by some marines during recruit training to refer to the National Defense Service Medal, so named for the red and yellow appearance, like the cheese and sauce of a pizza.
platoon sergeant – SNCO executive to the platoon commander, usually the senior enlisted man.
PMCM - Equipment such as aircraft that are partially mission capable due to maintenance that needs to be performed. Parts are available but not manpower.
PMCS – Preventive Maintenance Checks and Services, regularly performed maintenance on equipment, as opposed to corrective maintenance.Also, partial mission capability of equipment such as aircraft due to parts shortage in the supply chain.
pogue or POG – Marine not of the combat arms (infantry), etymology is disputed: possibly "pogue" derived from the Tagalog word meaning "prostitute" or the Erse Gaelic word meaning "to kiss [my ass]", while "POG" could be from the acronym Persons Other than Grunt, but could be a backronym.
poguey or pogey bait – Candy or sweets. See also geedunk.
pot shack – place where cooking utensils are washed.
possible – slang term for the highest score possible in a marksmanship exercise as in "shooting a possible"; used on the rifle range during Recruit Training to denote the shooter possibly achieving a perfect score in a given round of firing.
prick – slang for any equipment bearing the "PRC" JETDS designator, usually man-portable radios.
Pro & Cons - Contraction of "Proficiency and Conduct marks", a numeric system for evaluating enlisted Marines. Usually written or spoken consecutively, with the first being Proficiency and the second being Conduct, e.g. 4.5/4.8. Hypothetically, the scale is from 0.0 to 5.0, but a perfect 5.0 is so rare that a Marine who receives it is called a "water-walker" (in reference to Mark 6:48) and the worst marks awarded almost never fall below 2.0 .
property shed – place where organizational property is stored, often a warehouse.
QRF – Quick Reaction Force, a highly-mobile stand-by force designed to add firepower in precise places as the commander decides on a changing battlefield, often used for MEDEVAC purposes.
quarter deck – a location of prominence in a barracks or office; in recruit training, this area by the drill instructor's office is usually off-limits to recruits except during ceremonial discipline; the term comes from the quarter deck of a ship defined as "the part of the upper deck abaft the mainmast, including the poop deck when there is one. Usually reserved for ship's officers, guests, and passengers."
quarterdecking – incentive training at recruit training by means of repetitive and constant physical exercises, so named because it is usually a recruit's only opportunity to visit the quarter deck. See also pitting.
quarters – housing, whether bachelor (barracks) or family (government-leased apartments or houses); or periodic, muster of a ship's company.
quatrefoil – four-pointed embroidered pattern stitched on to the top of a Marine officer's barracks cover, from the tradition of wearing it to be identified as friendly to Marine sharpshooters during boarding actions in the era of wooden sailing ships.
Red Patch – device worn on the uniforms of landing support Marines to distinguish the shore party from landing troops.
request mast – appealing to increasingly higher links in the chain of command in order to seek satisfaction for a grievance the requester feels was not adequately handled at a lower level; DoN orders permit any Marine to request mast up to the individual's commanding general without repercussions.
re-up – reenlist, volunteering for an additional period of service.
RFI – Request For Information.
roach coach - civilian vehicle allowed on base to sell fast food (see Pogey Bait).
ROE – Rules Of Engagement, the restrictions on when and how a servicemember may use force on the enemy and other forces.
rubber bitch – affectionate name given to the ISO mat or sleeping pad which is made of a rubber foam like material. It is used by Marines when sleeping on the ground or other hard surfaces. It is sometimes used during PT (physical training) for calisthenics.
running lights – navigational night lights on a ship; Marine's eyes.
SACO – Substance Abuse Control Officer, a Marine responsible for the initial screening and evaluation of a Marine or sailor with alcoholism or illegal drug use issues to the proper medical facilities for rehabilitation & treatment.
S/F – abbreviation for Semper Fidelis when used as an end greeting in written communication.
sailor – the following nicknames are usually acceptable: bluejacket, tar, whitehat; while the following are considered insults: gob, swab, swabbie, swab jockey, squid, anchor clanker, rust picker, deck ape.
salad, tossed salad or fruit salad – ribbons and medals worn on a uniform, from the colorful appearance of wearing many awards.
salt, salty, or salt/salty dog – experienced or well-worn person or object, from the salt that would accumulate after long-term exposure to salt water.
SARC – Sexual Assault Response Coordinator, a Marine (usually an SNCO) assigned as the point of contact for personnel who are victims of or witnesses to sexual assault. Such duty is often ironically assigned to one of the least tactful/sensitive members of a unit.
say again (your last) – request to repeat a statement, question, or order, especially over a radio, or as "I say again" to preface a repetition by the sender; the word "repeat" is not to be used in this context, as it calls for a preceding fire mission to be fired again.
scuttlebutt – gossip; or a drinking fountain, from "butt" (cask) and "scuttle" (a hole in a ship's side at deck level that allows water to drain from the deck), a cask that had an opening fitted with a spigot used to contain fresh water for drinking purposes. Because people gathered around a scuttlebutt, gossip, rumors, and sea stories are also known as scuttlebutt.
seabag or sea bag – duffel bag used to carry one's personal belongings. "Duffel bag" is an Army term not used by Marines.
seabag drag – manually carrying personal items (often within seabags) to new or temporary living quarters.
sea lawyer – person who dispenses legal advice without any sort of formal training or schooling, inappropriately called a "barracks lawyer".
sea story – story, tale, or yarn calculated to impress others, often contains exaggeration or even outright lies.
second award – used in conjunction with a promotion to denote achieving a rank for the second time after being previously busted as in "Lance Corporal – Second Award"; derived from the devices worn with marksmanship badges denoting multiple awards of the expert classification.
Semper Fi – shortened version of "Semper Fidelis", the motto of the Corps, Latin for "always faithful". Can be used ironically, as in, "Semper Fi, Mac," which basically means, "That's the breaks," or "Too fucking bad."
Semper Fi fuck your buddy – colloquialism version of "Semper Fidelis", used ironically, as in, "Semper Fi, fuck your buddy," which denotes commiseration when a fellow Marine feels he/she's been inconvenienced or screwed over by the Marine Corps, a Marine peer or superior."
short-timer – person nearing the completion of his/her present tour of duty or enlistment.
short-timer's disease – apathy to duties and regulations from a person nearing EAS.
shove off – to leave the vicinity, from the naval term meaning to push a boat off the shore or pier.
shower shoes – pair of rubber sandals issued to recruits to prevent infections from the use of community or shared showers. See also Jesus shoes. Also sometimes used as a facetious, almost-always joking pejorative term for new Marines. That is to say that they're so new that they don't even rate to be called "boots". See also: Boot
sick bay – infirmary or other medical facility aboard ship, can also refer to aid stations ashore. See also BAS.
sick call – daily period when routine ailments are treated at sick bay.
skate – avoiding work by finding an excuse to be elsewhere or unavailable by doing something easier (but important enough to avoid re-tasking); also used as an adjective to describe such an easier duty.
skipper – nickname for captain (whether Marine or Navy rank), derived from the Scandinavian word for ship, "schiffe", and the Dutch word for captain, "schipper". Inappropriate to refer to a commanding officer that is not your own or without permission.
smokin' and jokin' – when a mass of Marines is acting unproductive.
SNCOIC – Staff NonCommissioned Officer In Charge, a SNCO responsible for a group of Marines, but without the authority of a commissioned officer; somes also the senior enlisted Marine acting with the officer in charge. See also NCOIC & OIC.
snap in – conduct sighting in or aiming exercises with an unloaded weapon.
SRB – Service Record Book, an administrative record of an enlisted Marine's personal information, promotions, postings, deployments, punishments, and emergency data; much like an officer's OQR.
SSDD – Same Shit, Different Day, euphemism denoting frustration with an unchanging situation or boredom.
stacking swivel – oblong-shaped link with an opening screwed to the rifle that allowed other rifles to be hooked and stacked (the M1 Garand was the last service rifle to have a stacking swivel, this function is now held by the weapon's sling); "Grab him by the stacking swivel" infers grabbing a person's throat.
tip of the spear – term for a unit or subunit that enters enemy territory first.
T/O&E – Table of Operations and Equipment, a list authorizing a unit personnel of a particular rank and MOS, as well as organic equipment; often seen separately as T/O and T/E.
toilet bowl – Marksman Weapons Qualification Badge, so named for the concentric rings in the design which resemble water swirling down a toilet bowl, and in allusion to its being the lowest level of weapons qualification. See also pizza box.
top – informal nickname for a Master Sergeant, inappropriate to use without permission.
trooper – soldier, considered a grievous insult to refer to a Marine unless plural.
TS Chit – A (fictitious) small card, to be punched by a senior person upon hearing a high-grade TS (very sad) story. When completely punched around the edge, the bearer is entitled to a half hour with the chaplain. "That story is so sad I'll punch your TS Chit twice."
two-block – hoist a flag or pennant to the peak, truck, or yardarm of a staff; or a tie with the knot positioned exactly in the gap of a collar of a buttoned shirt. Correctly, "to-block"—hoisted all the way to the block (pulley) at the top of signal halliard.
two digit midget— an enlisted Marine with 99 or fewer days remaining on his or her enlistment.
UD – Unit Diary, the computerized system that maintains all administrative records for a unit. Also, Uniform of the Day (or UDs) - prescribed uniform for the day; more generally associated with 'Charlies'
un-ass or un-fuck – to correct a deficiency, usually on a person.
under arms – status of having a weapon, sidearm, "MP" or "SP" brassard, or wearing equipment pertaining to an arm such as a sword sling, pistol belt, or cartridge belt as part of guard duty; Marines under arms do not remove covers indoors.
under canvas – living under temporary sheltering, such as a tent.
under way – to depart or to start a process for an objective.
unq – unqualified, usually in reference to training events.
unsat – abbreviation of unsatisfactory.
USMC – Acronym for United States Marine Corps. Also used as a pejorative backronym: Uncle Sam's Misguided Children, U Signed the Motherfucking Contract, U Suckers Missed Christmas, Unlimited Shit and Mass Confusion, University of Science, Music and Culture, Uncomplicated Shit Made Complicated, Under Seabee Management Constantly.
wing wiper – aviation person, usually a maintenance person and not a pilot.
winger – aviation Marine.
WIR – DRMO; Washed-out In Repair; waste incidental to reprocessing; collection of items and/or equipment for turn-in that may be re-used by someone else at a later time, preferably at a savings to the government.
the wire – defensive perimeter of a firm base, crossing it denotes the end of relative safety.
word – general term for instructions, orders, and information that is required for all members of a unit to know; or the act of passing information to a collected group of servicemembers. See also gouge.
WM – unofficial acronym for a female Marine. Some consider it a pejorative.
work your bolt – resort to special measures, either by energy or guile, in order to attain a particular end; from the action of racking a rifle's bolt to clear a stoppage.
zero – pronounced zee-row in an exaggerated manner, as used by Drill Instructors at the end of a count-down implying that recruits are to immediately cease all activity remain silently in place. Used by Marines to gain the immediate attention of all personnel in the area without calling attention on deck.
zero-stupid thirty – an unnecessarily early time for which personnel are required to assemble for an activity. See also O-dark thirty.