An Etymological Dictionary of the German Language/Annotated/Werwolf
Werwolf, masculine, ‘werewolf,’ from the equivalent Middle High German wërwolf (not recorded in Old High German). It is undoubtedly based on an Old Teutonic word; compare Anglo-Saxon wërewulf, English werewolf. From the Anglo-Saxon word is derived Middle Latin guerulfus, Old French garou, whence by tautology Modern French loup-garou, ‘werewolf.’ The presupposed Old Teutonic werowulfo- means literally ‘man-wolf,’ i.e., a man who roams about in the form of a wolf (Greek λυκάνθρωπος). The first component is Old High German, Old Saxon, and Anglo-Saxon wër (Gothic waír), masculine, ‘man,’ primitively cognate with Latin vir, Sanscrit vîras, ‘man.’