Pol"y*chrest (?), n. [Gr. &?; useful for many purposes; poly`s many + &?; useful, fr. &?; to use: cf. F. polychreste.] (Med.) A medicine that serves for many uses, or that cures many diseases. [Obs.]

Polychrest salt(Old Med. Chem.), potassium sulphate, specifically obtained by fusing niter with sulphur.