An Etymological Dictionary of the German Language/Annotated/Feind
Feind, masculine, ‘enemy, foe, fiend,’ from Middle High German vînt, vîent, vîant, Old High German fîant, masculine, ‘enemy’; the common Teutonic noun for ‘enemy’; compare Old Saxon fîund, Anglo-Saxon feónd, English fiend, Old Icelandic fjánde, Gothic fijands. In contrast to Latin hostis, discussed under Gast, the Teutonic designates his enemy according to the disposition of the latter; Feind (present participle of the Sanscrit root pî, pîy, ‘to scorn, hate’) is literally ‘the hater’; compare Old High German fîen, Anglo-Saxon feógan, Gothic fijan, ‘to hate,’ akin to Gothic faian, ‘to blame.’ Fehde is perhaps allied to it; for the transformation of the present participle into a substantive compare also Freund, Weigand, and Heiland.