A clapper board; a device used in film production, having hinged boards that are brought together with a clap, used to synchronize picture and sound at the start of each take of a motion picture or other video production.
A narrow board, usually thicker at one edge than the other, used as siding for houses and similar structures of frame construction.
Such boards, arranged horizontally and overlapping with thick edge down, collectively, as siding.
To cover with clapboards.