a mixture of lime, hair and sand, used to cover rough walling of lathwork between timbers (see Plasterwork); also a fine white plaster of gypsum, generally known. as "plaster of Paris." The word (also as "plaister") is used in medicine of adhesive mixtures employed externally for the protection of injured surfaces, for support of weak muscular or other structures, or as counter-irritants, soothing applications &c. The ultimate derivation of the word is the Gr. gparXavrpov or eµirXao-rov in the medical sense, from iv, on, and 7rMaoew, to daub or smear.