clapboard (klăbˈərd) [key], board used for the exterior finish of a wood-framed building and attached horizontally to the wood studs. The word, in its original and strict use, refers to a product of New England; boards of similar type made elsewhere are termed siding. Clapboards are particularly characteristic of the United States, having been steadily used since the earliest years of the colonial settlements. Each clapboard overlaps the one below it, leaving a few inches exposed to the weather. White pine is considered the best wood for clapboards; cedar, cypress, and spruce are also used.