The Collaborative International Dictionary of English v.0.48:

Loup-garou \Loup`-ga`rou"\, n.; pl. Loups-garous. [F., fr.
   loup wolf + a Teutonic word akin to E. werewolf.]
   A werewolf; a lycanthrope.
   [Webster 1913 Suppl.]

         The superstition of the loup-garou, or werewolf,
         belongs to the folklore of most modern nations, and has
         its reflex in the story of "Little Red Riding-hood" and
         others.                                  --Brinton.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

loup-garou
    n 1: a monster able to change appearance from human to wolf and
         back again [syn: werewolf, wolfman, lycanthrope,
         loup-garou]