Definition of "clapboard"

A narrow board, usually thicker at one edge than the other, used as siding for houses and similar structures of frame construction.  quotations  examples

(uncountable) Such boards, arranged horizontally and overlapping with thick edge down, collectively, as siding.  examples

(archaic, UK) An oak board of a size used for barrel staves.

(transitive) To cover with clapboards.  examples

(film) 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.  examples