rancid [E17th] Latin rancidus which means ‘stinking’ is the source of rancid in English. The related rancor ‘rankness’ gives us rancour [ME].
英语词源词典收录了6069条英语词源词条，基本涵盖了全部常用英语词汇的起源、历史，是研究英语词汇或通过词源学英语的必备工具。