pre-youdaoicibaDictYouDict[pre- 词源字典]
word-forming element meaning "before," from Old French pre- and Medieval Latin pre-, both from Latin prae (adverb and preposition) "before in time or place," from PIE *peri- (cognates: Oscan prai, Umbrian pre, Sanskrit pare "thereupon," Greek parai "at," Gaulish are- "at, before," Lithuanian pre "at," Old Church Slavonic pri "at," Gothic faura, Old English fore "before"), extended form of root *per- (1) "beyond" (see per).

The Latin word was active in forming verbs. Also see prae-. Sometimes in Middle English muddled with words in pro- or per-.[pre- etymology, pre- origin, 英语词源]