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.