(n) wallboard with a gypsum plaster core bonded to layers of paper or fiberboard; used instead of plaster or wallboard to make interior walls, Syn. gypsum board
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
n. [ L. gypsum, Gr. gy`psos; cf. Ar. jibs plaster, mortar, Per. jabsīn lime. ] (Min.) A mineral consisting of the hydrous sulphate of lime (calcium). When calcined, it forms plaster of Paris. Selenite is a transparent, crystalline variety; alabaster, a fine, white, massive variety. [ 1913 Webster ]