rancid (adj.)youdaoicibaDictYouDict[rancid 词源字典]
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 etymology, rancid origin, 英语词源]
rancor (n.)youdaoicibaDictYouDict
c. 1200, from Old French rancor "bitterness, resentment; grief, affliction," from Late Latin rancorem (nominative rancor) "rancidness, a stinking smell" (Palladius); "grudge, bitterness" (Hieronymus and in Late Latin), from Latin rancere "to stink" (see rancid).