Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.

WORD ORIGIN

Old English gist "yeast," common West Germanic (cf. Middle High German gest, German Gischt "foam, froth," Old High German jesan, German gären "to ferment"), from PIE *jes- "boil, foam, froth" (cf. Sanskrit yasyati "boils, seethes," Greek zein "to boil," Welsh ias "seething, foaming").