Real Dictionary

clapboard
A clapboard building has walls which are covered with long narrow pieces of wood, usually painted white.
countable noun: A clapboard is the same as a clapperboard.

clapboard in American English
a long, narrow board with one edge thicker than the other, used as siding
to cover with clapboards

clapboard in American English 1
adjective: of or made of clapboard
noun: a long, thin board, thicker along one edge than the other, used in covering the outer walls of buildings, being laid horizontally, the thick edge of each board overlapping the thin edge of the board below it

clapboard in American English 2
noun: a small board with a hinged stick attached that is clapped down at the beginning of the filming of a shot for use later in synchronizing sound and image in the editing of the film

clapboard in British English
noun: a long thin timber board with one edge thicker than the other, used esp in the US and Canada in wood-frame construction by lapping each board over the one below
verb: to cover with such boards