lingula /lingˈgū-lə/ noun

1. A little tongue-like part
2. (with cap) a narrow-shelled genus of brachiopods
3. Extended loosely to related genera, such as Lingulellˈa, the characteristic fossil of the Upper Cambrian Lingula Flags

lingˈular adjective

Relating to a lingula

lingˈulate adjective

Tongue-shaped

lingua franca /lingˈgwə frangkˈə/ noun (pl lingue franche /lingˈgwā frangkˈā/ or lingua francas)

1. (Ital, Frankish language) orig a mixed Italian trade jargon used in the Levant
2. A language chosen as a medium of communication among speakers of different languages
3. Any hybrid language used for the same purpose
4. The familiar conventions of any style, esp in music or the arts, readily recognized and understood by devotees

linguistic atlas or linguistic map noun

An atlas or map that charts the spread and distribution of features of a language or dialect, such as pronunciation or vocabulary

linguistic philosophy or linguistic analysis noun

1. A term loosely used to cover methods of analysis of philosophically puzzling concepts by the meticulous assembly and scrutiny of the widely-varying expressions of these concepts in ordinary discourse
2. Later extended to a systematic study of the working of language itself