Argot (French, Spanish, Catalan for "slang is a language used by various groups, to prevent outsiders from understanding their conversations. The term argot is also used to refer to the informal specialized vocabulary of study, hobby, job, sport, etc. Victor Hugo was one of the first to research argot extensively. He describes it in his novel, Les Miserables.

Sterling defines argot as "the deliberately hermetic language of a small knowledge clique... a super-specialized geek cult language that has no traction in the real world."

The earliest known recording of the term "argot" was in 1628, and the word probably derives from the name, les argotiers, given to a group of thieves at that time.