Origin of werewolfMiddle English werwolf from Old English werwulf from wer, man from Indo-European an unverified form wiros, man (prob. origin, originally , “the strong one” from base an unverified form wei-, to be strong from source Classical Latin vis, power, vir, man) + Old English wulf, wolf
Origin of werewolfMiddle English from Old English werewulf wer man ; see wī-ro- in Indo-European roots. wulf wolf ; see wolf . Word History: The meaning wolf in werewolf is current English; the were is not. Werewulf, “werewolf,” occurs only once in Old English, about the year 1000, in the laws of King Canute: “ lest the madly ravenous werewolf too savagely tear or devour too much from a godly flock. ” The wer- or were- in wer(e)wulf means “man”; it is related to Latin vir with the same meaning, the source of virile and virility. Both the Germanic and the Latin words derive from Indo-European *wīro-, “man.” Wer- also appears, though much disguised, in the word world. World is first recorded (written wiaralde ) in Old English in a charter dated 832; the form worold occurs in Beowulf. The Old English forms come from Germanic *wer-ald-, “were-eld” or “man-age.” The transfer of meaning from the age of humans to the place where they live has a parallel in the Latin word saeculum, “age, generation, lifetime,” later “world.”
From Middle English werwolf, from Old English werwulf (“werewoulf", literally “man-wolf"), equivalent to wer +"Ž wolf or were- +"Ž wolf. Cognate with Dutch weerwolf (“werewolf"), Middle Low German werwulf, werwolf, warwulf (“werewolf"), German Werwolf (“werewolf"), Danish varulv (“werewolf"), Swedish varulv (“werewolf"). Compare also French garou, in loup-garou (“werewolf"), French dialectal gairou, varou (“werewolf"), Medieval Latin gerulphus, garulphus (“werewolf") (< Germanic).