Source : Webster's Revised Unabridged Dictionary (1913)

Crowberry \Crow`ber`ry\ (kr?"b?r`r?), n. (Bot.)
   A heathlike plant of the genus {Empetrum}, and its fruit, a
   black, scarcely edible berry; -- also called {crakeberry}.

Source : WordNet®

crowberry
     n : a low evergreen shrub with small purple flowers and black
         berrylike fruit