Deppermann, Arnulf (2016): La définition comme action multimodale pour des enjeux pratiques : définir pour instruire à l'auto-école. In: Langage 204 (4), S. 83-101. Abstract: Drawing on a corpus of 70 hours of video-recordings from driving school lessons in German, this paper studies the design of definitions of technical terms by driving school instructors. Definitions are produced for all practical purposes, tied to learning goals concerning the correct handling of the car. It is shown that the activity of defining in this setting crucially makes use of multimodal resources. Ostensive definition by pointing and an existential statement (this/here is X) is complemented by descriptive definitions and the enactment of the handling of objects. The definitions provided do not purport to be context-free definitions of the term per se. They are rather fragmented, indexical and context-sensitive, relying heavily on presupposed background knowledge of the recipient.