Stories We Like: A Guide to the Comma
1640s, from Latin rancidus "rank, stinking, offensive" (also source of Italian rancido, Spanish rancio), from rancere "be spoiled or rotten," of unknown origin. German ranzig is from French rancide. Related: Rancidness.
rancid ran·cid (rān'sĭd)
Having the disagreeable odor or taste of decomposing oils or fats.