Lunfardo is a colorful argot of the Spanish language which developed at the end of the 19th century and beginning of the 20th century in the lower classes in and around Buenos Aires.

Many Lunfardo expressions have entered into the popular language and have become an integral part of the Spanish spoken in Argentina and Uruguay. A few have been recognized even by the "Real Academia Española". Lunfardo is frequently found in the lyrics of tangos, supplying nuances and double-entendres with overtones of sex, drugs, and the criminal underworld.

Much of Lunfardo arrived with European immigrants, such as Italians, French, Portuguese, and Poles. It should be noted that Italian immigrants spoke their regional dialects and not standard Italian; other words arrived from the pampa by means of the gauchos; a small number originated in Argentina's black population.

Most sources believe that Lunfardo originated in jails, as a prisoner-only argot. Circa 1900, the word lunfardo itself (originally a deformation of lombardo in several Italian dialects) was used to mean "outlaw".

Bailongo: lunfardo for a place where people dance, i.e. a "Milonga".

Bacán: lunfardo for a wealthy man or one who pretends to be wealthy. A man who keeps a woman. A pimp who owns a woman. A concubine of a prostitute.
 
Cana: lunfardo for the police, a policeman or the jail.

Canyengue: lunfardo word with several meanings. It refers to somebody or something from the slums, i.e. low class. It also describes a gathering where people from the slums dance. It is also a certain way to perform or dance the tango with a slum attitude. Finally, it is a rhytmic effect created by Leopoldo Thompson by hitting the string of the contrabass with the hand or the arch of the bow.

Carancanfunfa: in the lingo of the compadritos, the dance of tango with interruptions (cortes) and also those who dance it that way in a very skillful manner.
 
Gavión: lunfardo for a libertine man who seduces women. A Don Juan that charms the women. A seducer, a mocker.

Grelas: lunfardo for woman.

Mishiadura: lunfardo for poverty.

Mina: lunfardo for woman.

Paicas: a lunfardo word for girl.

Pebeta: lunfardo for young woman or girl.

Reo: lunfardo for hobo, unemployed, given to partying and reticent to work. Typical of people of lower class status. Also, it is used as humble, poor.

Shusheta: lunfardo for a person who takes excessive care of his posture and attire. Also it is used to describe a police informant, a person who accuses in secret, a snitch. A fop, a dandy.