Definition of clapboards:
(n) :
A narrow board, usually thicker at one edge than the other, used as siding for houses and similar structures of frame construction.
(n) :
(uncountable) Such boards, arranged horizontally and overlapping with thick edge down, collectively, as siding.
(n) :
(film) A clapperboard; 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.
(v) :
(transitive) To cover with clapboards.
(n) :
(archaic, UK) An oak board of a size used for barrel staves.