شِيدٌ

Anything with which a wall is plastered, (S, A, K,) consisting of gypsum and the like; (A, K;) J says, of gypsum or بَلَاط; but this last word is a mistake, [probably originated by an early transcriber of the S,] for مِلَاط, i. e. mud, or clay: (K:) or [peculiarly] gypsum. (Msb.)

Az says that some of the Arabs sometimes call thus A حِصْن [i. e. fortress, fort, or fortified place]. (TA.)