Lunfardo is a dialect originated and developed in the late 19th and early 20th centuries in the lower classes in Buenos Aires and the surrounding Gran Buenos Aires, and from there spread to other cities nearby, such as Rosario and Montevideo, cities with similar socio-cultural situations. Originally, Lunfardo was a slang used by criminals and soon by other people of the lower and lower-middle classes. Later, many of its words and phrases were introduced in the vernacular and disseminated Castilian of Argentina and Uruguay. Nevertheless, since the early 20th century, Lunfardo began to spread among all social strata and classes, either by habitual use or because it was common in the lyrics of tango. During the 20th and this century many of its words have gone to neighboring countries like Chile and Paraguay, because immigrants from those countries are living in Argentina.
A few have been recognized even by the Real Academia Española.
Lunfardo (or briefly, lunfa) began as prison slang in the late 19th century, so guards would not understand the prisoners.
Most sources believe that Lunfardo originated among criminals, and later became more commonly used by other classes. Circa 1900, the word lunfardo itself (originally a deformation of lombardo in several Italian dialects) was used to mean "outlaw".
Lunfardo today 
Today, some Lunfardo terms have entered in the language spoken all over Argentina and Uruguay, while a great number of Lunfardo words have fallen into disuse or have been modified in the era of suburbanization. Furthermore, the term "Lunfardo" has become a synonymous with "speech of Buenos Aires", mainly of the inhabitants of the City of Buenos Aires, and its surrounding areas (Greater Buenos Aires). The Montevideo speech has almost as much "lunfardo slang" as the Buenos Aires speech.
Lunfardo words are inserted in the normal flow of Rioplatense Spanish sentences. Thus, an average Spanish-speaking person reading tango lyrics will need, at most, the translation of a discrete set of words, and not a grammar guide.
Tango lyrics use lunfardo sparsely, but some songs (such as El Ciruja, or most lyrics by Celedonio Flores) employ lunfardo heavily. "Milonga Lunfarda" by Edmundo Rivero is an instructive and entertaining primer on lunfardo usage.
A characteristic of lunfardo is its use of word play, notably vesre (from "[al] revés", reversing the syllables, similar to English spoonerisms). Thus, tango becomes gotán and café con leche (coffee with milk) becomes feca con chele.
Finally, there are words that are derived from others in Spanish, such as the verb abarajar, which means to stop a situation or a person (e.g. to stop your opponent's blows with the blade of your knife) and is related to the verb "barajar", which means to cut or shuffle a deck of cards.
- buchón - snitch, informer to the law (from the French bouillon)
- chochamu - young man (vesre for muchacho)
- fiaca - laziness, or lazy person (from the Italian fiacco "weak")
- gomías - friends (vesre for amigos)
- guita - money
- lorca - hot, as in the weather (vesre for calor "heat")
- mina - an informal word for woman
- percanta - a young woman
- pibe - like "kid", a common term for boy or, in more recent times, for young man
- quilombo - racket, ruckus, disorder, mess; also slang for brothel (from the Kimbundu word kilombo).
- cerebrar - to think something up (from cerebro, "brain")
- engrupir - to fool someone (origin unknown, but also used in modern European and Brazilian Portuguese slang)
- garpar - to pay with money (vesre for pagar "to pay")
- junar - to look to / to know (from Caló junar "to hear")
- laburar - to work (from Italian lavorare "to work")
- manyar - to know / to eat (from the Italian mangiare "to eat")
- morfar - to eat (from French argot morfer "to eat")
- pescar - to know (vesre from the Italian capisce "do you understand?")
Modern slang 
Since the 1970s, it is a matter of debate whether newer additions to the slang of Buenos Aires qualify as lunfardo. Traditionalists argue that lunfardo must have a link to the argot of the old underworld, to tango lyrics, or to racetrack slang. Others maintain that the colloquial language of Buenos Aires is lunfardo by definition.
Some examples of modern talk:
- Gomas (lit. tires) - woman's breasts
- Maza (lit. mace or sledgehammer) - superb
- Curtir (lit. to tan) - to be involved in
- Curtir fierros can mean "to be into car mechanics" or "to be into firearms"[notes 1]
- Zafar - to barely get by[notes 2]
- Trucho - counterfeit, fake[notes 3]
Many new terms had spread from specific areas of the dynamic Buenos Aires cultural scene: invented by screenwriters, used around the arts-and-crafts fair in Plaza Francia, culled from the vocabulary of psychoanalysis.
A rarer feature of Porteño speech that can make it completely unintelligible is the random addition of suffixes with no particular meaning, usually making common words sound reminiscent of Italian surnames. These endings include -etti, -elli eli, -oni, -eni, -anga, -ango, -enga, -engue, -engo, -ingui, -ongo, -usi, -ula, -usa, -eta, among others.
See also 
- Fierro is the Old Spanish form of hierro (iron). In Argentine parlance, it can mean a firearm or anything related to metals and mechanics, for example a racing car.
- Zafar is actually a standard Spanish verb (originally meaning to extricate oneself) that had fallen out of use and was restored to everyday Buenos Aires speech in the 1970s by students, with the meaning of "barely passing (an examination)".
- Trucho is from old Spanish slang truchamán, which in turn derives from the Arabic turjeman ("translator", referring specifically to a person who accosts foreigners and lures them into tourist traps). Folk etymology derives this word from trucha (trout), or from the Italian trucco, something made fake on purpose. Reference (Spanish)
- Lunfardo history, with historical accounts in newspapers of the nineteenth century.
- Definition of the word "Lunfardo"according to the RAE.
- Grayson, John D. (March 1964). "Lunfardo, Argentina's Unknown Tongue". Hispania (American Association of Teachers of Spanish and Portuguese) 47 (1): 66–68. doi:10.2307/337280.
- pibe in the Diccionario de la Real Academia Española.
- (English) "Porteño Spanish - Learn Argentine Slang"
- (English) "A Survivors Guide To Buenos Aires"
- (English) "Gringo Lingo: A Guide to Buenos Aires Slang, Common Grammar Mistakes and much more"
- (English) "Lunfardo-English Online translation and help"
- (English)(Spanish) "CheViste - Lunfardo Dictionary"
- (Spanish) Diccionario del lunfardo
- (Spanish) Course description - Includes extensive bibliography
- (Spanish) What is lunfardo
- (Spanish) Lunfardo Dictionary
- (Spanish) Lunfardo etymology
- (Spanish) Defining Lunfardo
- (Spanish) Lunfardo's history
- (Spanish) Academia Porteña del Lunfardo
- (Spanish) Traducción y ayuda online