The Collaborative International Dictionary of English v.0.48:

Guevi \Gue"vi\, n. (Zool.)
   One of several very small species and varieties of African
   antelopes, of the genus Cephalophus, as the Cape guevi or
   kleeneboc (Cephalophus pygm[ae]a); -- called also pygmy
   antelope.
   [1913 Webster]