The Collaborative International Dictionary
wasteboard
Washboard \Wash"board`\, n.
A fluted, or ribbed, board on which clothes are rubbed in washing them.
A board running round, and serving as a facing for, the walls of a room, next to the floor; a mopboard.
(Naut.) A broad, thin plank, fixed along the gunwale of boat to keep the sea from breaking inboard; also, a plank on the sill of a lower deck port, for the same purpose; -- called also wasteboard.
--Mar. Dict.
Wiktionary
wasteboard
n. (context nautical English) (archaic form of washboard English)