Source : Webster's Revised Unabridged Dictionary (1913)

Dewberry \Dew"ber`ry\, n. (Bot.)
   (a) The fruit of certain species of bramble ({Rubus}); in
       England, the fruit of {R. c[ae]sius}, which has a
       glaucous bloom; in America, that of {R. canadensis} and
       {R. hispidus}, species of low blackberries.
   (b) The plant which bears the fruit.

             Feed him with apricots and dewberries. --Shak.

Source : WordNet®

dewberry
     n 1: any of several trailing blackberry brambles especially of
          North America [syn: {dewberry bush}, {running blackberry}]
     2: blackberry-like fruits of any of several trailing blackberry
        bushes