slang, cant, jargon, lingo, argot, patois, vernacular (noun)

a characteristic language of a particular group (as among thieves)

"they don't speak our lingo"

argot (Noun)

A secret language or conventional slang peculiar to thieves, tramps and vagabonds.

argot (Noun)

The specialized informal vocabulary and terminology used between people with special skill in a field, such as between doctors, mathematicians or hackers; a jargon.

Argot

An argot is a secret language used by various groups—including, but not limited to, thieves and other criminals—to prevent outsiders from understanding their conversations. The term argot is also used to refer to the informal specialized vocabulary from a particular field of study, hobby, job, sport, etc. The author Victor Hugo was one of the first to research argot extensively. He describes it in his 1862 novel Les Misérables as the language of the dark; at one point, he says, "What is argot; properly speaking? Argot is the language of misery." The earliest known record of argot was in a 1628 document. The word was probably derived from the contemporary name, les argotiers, given to a group of thieves at that time. Under the strictest definition, an argot is a proper language, with its own grammar and style. But, such complete secret languages are rare, because the speakers usually have some public language in common, on which the argot is largely based. Argots are mainly versions of other languages with a part of its vocabulary replaced by words unknown to the larger public. For example, the term is used to describe systems such as verlan and louchébem, which retain French syntax and apply transformations only to individual words. Such systems are examples of argots à clef, or "coded argots."

argot

A cant is the jargon or language of a group, often employed to exclude or mislead people outside the group. It may also be called a cryptolect, argot, pseudo-language, anti-language or secret language. Each term differs slightly in meaning; their use is inconsistent.