Noun Concept
Categories: Pidgins and creoles, Interlinguistics, Language varieties and styles, Articles with short description, Linguistics terminology
slang  cant  jargon  lingo  argot
A characteristic language of a particular group (as among thieves) WordNet 3.0
A cant is the jargon or language of a group, often employed to exclude or mislead people outside the group. Wikipedia
A secret language Wikipedia Disambiguation
Language term for jargon or argot of a group Wikidata
Secret language Wikidata
Terminology which is especially defined in relationship to a specific activity, profession, group, or event. OmegaWiki
Language or dialect native to a region, as distinct from the standard language. OmegaWiki
A secret or private language used by various groups to prevent outsiders from understanding their conversations. OmegaWiki
A private or secret language used by a religious sect, gang, or other group. Wiktionary
Secret language. Wiktionary (translation)
Language characteristic of a particular group. Wiktionary
Language, especially language peculiar to a particular group, field, or region; jargon or a dialect. Wiktionary
Language peculiar to a particular group or region. Wiktionary (translation)
The specialized language of a social group, sometimes used to make what is said unintelligible to those not members of the group; cant. Wiktionary
Language unique to a particular group of people; jargon, argot. Wiktionary
Language unique to a particular group of people. Wiktionary (translation)
They don't speak our lingo WordNet 3.0 & Open English WordNet
For those of a certain age, hiphop vernacular might just as well be a foreign language. Wiktionary