- erstwhile (adv.)
[erstwhile 词源字典]
- 1560s, "formerly," from erst "first, at first; once, long ago; till now" (13c.), earlier erest from Old English ærest "soonest, earliest," superlative of ær (see ere) + while (adv.). As an adjective, "former," from 1903. Cognate with Old Saxon and Old High German erist, German erst.[erstwhile etymology, erstwhile origin, 英语词源]