Definitions
1.nounA narrow board, usually thicker at one edge than the other, used as siding for houses and similar structures of frame construction.
2.nounSuch boards, arranged horizontally and overlapping with thick edge down, collectively, as siding.
3.nounAn oak board of a size used for barrel staves.
4.nounA 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.