The Collaborative International Dictionary of English v.0.48:

Whinberry \Whin"ber*ry\, n. (Bot.)
   The English bilberry; -- so called because it grows on moors
   among the whins, or furze. --Dr. Prior.
   [1913 Webster]

WordNet (r) 3.0 (2006):

whinberry
    n 1: erect European blueberry having solitary flowers and blue-
         black berries [syn: bilberry, whortleberry,
         whinberry, blaeberry, Viccinium myrtillus]