fromyoudaoicibaDictYouDict[from 词源字典]
from: [OE] From goes back ultimately to Indo- European *pr, which also produced English first, for, fore, foremost, former, and before. The addition of a suffix -m gave a word denoting ‘forward movement, advancement’ (as in Greek prómos ‘foremost’). By the time it reached Old English as from or fram the notion of ‘moving forward or onward’ had passed into ‘moving away’. The related fro [12], now little used except in to and fro, comes from Old Norse frá.
=> before, first, for, fore, former, forth, fro, primary[from etymology, from origin, 英语词源]
from (prep., adv.)youdaoicibaDictYouDict
Old English fram, preposition denoting departure or movement away in time or space, from Proto-Germanic *fra "forward, away from" (cognates: Old Saxon, Old High German, Gothic fram "from, away," Old Norse fra "from," fram "forward"), from PIE *pro-mo-, suffixed form of *pro (see pro-); the Germanic sense of "moving away" apparently evolved from the notion of "forward motion." It is related to Old English fram "forward; bold; strong," and fremian "promote, accomplish" (see frame (v.)).