An Etymological Dictionary of the German Language/Annotated/fromm

fromm, adjective, ‘worthy, pious, harmless,’ from Middle High German vrum (inflected form vrumer), adjective, ‘able, excellent, good, gallant, conducive.’ The adjective is properly a substantive (compare Schade); Middle High German frum, fruma, Old High German fruma, ‘use, advantage’ (frummen, ‘to promote, accomplish’). Akin to the Anglo-Saxon forms with a gradation, fram, adjective, ‘brave, conducive,’ fremman, ‘to promote, accomplish’; compare Old Icelandic framr, ‘preferable,’ and fremja, ‘to execute.’ Also allied more remotely to the Old Teutonic terms for ‘primus.’ See Fürst, fort, fürder, &c.