a recording of a new song or of one performed by an unknown singer or singing group, distributed to disc jockeys, recording companies, etc., to demonstrate the merits of the song or performer.
4.
demolition(def. 1): He does flooring and demo for a living.
verb (used with object) dem·oed, dem·o·ing.
5.
to try out or exhibit the use of (a product, process, or the like): You can demo the game without downloading or buying it.
6.
to record (a song) to demonstrate the merits of the song or performer.