argot
noun
a specialized idiomatic vocabulary peculiar to a particular class or group of people, especially that of an underworld group, devised for private communication and identification.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
And then with rapid bird-like movements, and with her head on one side, Seraphine measured Lesbia's waist and bust, muttering little argotic expressions sotto voce as she did so.
From Phantom Fortune, a Novel by M. E. (Mary Elizabeth) Braddon