erstwhile
Word family adverbersterstwhile
erst·while /ˈɜːstwaɪl $ ˈɜːrst-/ adjectiveadj [only before noun] formal BEFOREformer or in the past 以前的;过去的 She found herself ostracized by erstwhile friends. 她发现自己被以前的朋友排斥。
his erstwhile allies 他以前的盟友
Origin erstwhile (1500-1600) erst “formerly” ((11-19 centuries)) (from Old English ærest “earliest”) + while