An Etymological Dictionary of the German Language/fromm
fromm, adj., ‘worthy, pious, harmless,’ from MidHG. vrum (inflected form vrumer), adj., ‘able, excellent, good, gallant, conducive.’ The adj. is prop. a subst. (comp. Schade); MidHG. frum, fruma, OHG. fruma, ‘use, advantage’ (frummen, ‘to promote, accomplish’). Akin to the AS. forms with a gradation, fram, adj., ‘brave, conducive,’ fremman, ‘to promote, accomplish’; comp. OIc. framr, ‘preferable,’ and fremja, ‘to execute.’ Also allied more remotely to the OTeut. terms for ‘primus.’ See Fürst, fort, fürder, &c.