Lunfardo (from the Italian lumbardo or inhabitant of Lombardy in the local dialect) is a dialect originated and developed in the late 19th and early 20th centuries in the lower classes in Buenos Aires and from there spread to other cities nearby, such as the surrounding area Greater Buenos Aires, Rosario and Montevideo. 
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 the Spanish of Argentina, and Uruguay. Nevertheless, since the early 20th century, Lunfardo has spread among all social strata and classes by habitual use or because it was common in the lyrics of tango.
Lunfardo (or lunfa for short) began as prison slang in the late 19th century so guards would not understand prisoners. According to Oscar Conde, the word came from "lumbardo" (the inhabitants of the region Lombardia in Italy, the origin of most of the Italians in Argentina in the early 19th century). However, the vernacular Spanish of mid-19th century Buenos Aires as preserved in the dialogue of Esteban Echeverría's short story The Slaughter Yard (El matadero) is already a prototype of Lunfardo.
Most sources believe that Lunfardo originated among criminals, and later became more commonly used by other classes. Circa 1870, the word lunfardo itself (originally a deformation of lombardo in several Italian dialects) was often used to mean "outlaw".
Today, some Lunfardo terms have entered in the language spoken all over Argentina and Uruguay, although 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 synonymous with "speech of Buenos Aires" or "Porteño", mainly of the inhabitants of the City of Buenos Aires, as well as its surrounding areas, Greater Buenos Aires. The Montevideo speech has almost as much "lunfardo slang" as the Buenos Aires speech. Conde says the lunfardo (much like the cocoliche) can be considered a kind of Italian dialect mixed with Spanish words, specifically the one spoken in Montevideo. In other words, the lunfardo is an interlanguage variety of the Italian dialects spoken by immigrants in the areas of Buenos Aires and Montevideo.
Conde has expressed that the Lunfardo is not so much a dialect but a kind of local language of the Italian immigrants, mixed with Spanish and some French words. He believes that Lunfardo is not a criminal slang, since most of the lunfardo words are not related to crime.
According to Conde, Lunfardo
...is a vernacular, or to put it more clearly, is a vocabulary of popular speech in Buenos Aires that spread first throughout the River Plate area and later to the whole country ... The use of this lexicon reminds speakers of their identity but also of their roots... lunfardo is possibly the only argot that was originally formed, and in great measure, from Italian immigrant terms. [Es un modo de expresión popular o, para decirlo más claramente, un vocabulario del habla popular de Buenos Aires…que se ha extendido primero a toda la región del Río de la Plata y luego al país entero…el uso de este léxico les recuerda a sus usuarios quiénes son, pero también de dónde vienen…el lunfardo es posiblemente el único que en su origen se formó, y en un alto porcentaje, con términos italianos inmigrados].
Lunfardo words are inserted in the normal flow of Rioplatense Spanish sentences, but grammar and pronunciation do not change. Thus, an average Spanish-speaking person reading tango lyrics will need, at most, the translation of a discrete set of words.
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 back slang, French verlan or Greek podaná. 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 (such as 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 Spanish buche a buchón is a type of dove)
- chochamu - young man (vesre for muchacho)
- fiaca - laziness, or lazy person (from the Italian fiacca "laziness, sluggishness")
- gomías - friends (vesre for amigos)
- guita - money
- gurí - boy, more recently used for young teenagers. Specific of Montevideo's speech
- gurisa - female for "gurí"
- lorca - hot, as in the weather (vesre for calor "heat")
- luca - 1000 pesos
- mango - an Argentine peso
- mina - an informal word for woman, from the Italian femmina
- percanta - a young woman
- pibe - like "kid", a common term for boy or, in more recent times, for young man
- quilombo - racket, ruckus, mess; also slang for brothel (from the Kimbundu word kilombo, a Maroon settlement).
- cerebrar - to think something up (from cerebro, "brain")
- engrupir - to fool someone (maybe from Italian ingroppare "to fuck", 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?")
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", 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 - to barely get by; 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 - counterfeit, fake; 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)
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.
- manyar (to eat) from Venetian and Lombard "magnar" (mangiare in Italian)
- lonyipietro (fool)
- fungi (mushroom) -> in Lunfardo: hat
- vento (wind) -> in Lunfardo: money
- matina (morning) from Italian "mattina"
- mina (girl) from Lombard "mina" (busty woman or prostitute)
- laburar (to work) from Italian "lavorare"
- minga (nothing) from Lombard "minga" (negative particle like not in English or ne pas in French)
- yeta (bad luck) from Neapolitan "iettatore"
- yira (to go for a walk) from Italian "girare"
- salute (cheers) from Italian "salute"
- fiaca (laziness) from Italian "fiacca"
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.
- Lunfardo history, with historical accounts in newspapers of the nineteenth century.
- Definition of the word "Lunfardo"according to the RAE.
- Conde. "Un estudio sobre el habla popular de los argentinos". Introduction
- The story may be read on Wikisource: https://es.wikisource.org/wiki/El_Matadero.
- Oscar Conde: Lunfardo. Un estudio sobre el habla popular de los argentinos; pág. 43
- Conde; p. 55
- Conde; p. 109
- pibe in the Diccionario de la Real Academia Española
- Cocoliche e Lunfardo: l'italiano dell'Argentina (in Italian). Archived 2016-02-22 at the Wayback Machine.
- A. Cancellier. Italiano e spagnolo a contatto nel Rio de La Plata Università di Milano. Milano, 2006
- Conde, Oscar. Lunfardo: Un estudio sobre el habla popular de los argentinos.Ediciones Taurus. Buenos Aires, 2011 ISBN 978-987-04-1762-0
- 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.