The Collaborative International Dictionary of English v.0.48:

Whortleberry \Whor"tle*ber`ry\, n. [AS. wyrtil a small shrub
   (dim. of wyrt wort) + E. berry. See Wort, and cf.
   Huckleberry, Hurtleberry.] (Bot.)
   (a) In England, the fruit of Vaccinium Myrtillus; also, the
       plant itself. See Bilberry, 1.
   (b) The fruit of several shrubby plants of the genus
       Gaylussacia; also, any one of these plants. See
       Huckleberry.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bilberry \Bil"ber*ry\, n.; pl. Bilberries. [Cf. Dan.
   b["o]lleb[ae]r bilberry, where b["o]lle is perh. akin to E.
   ball.]
   1. (Bot.) The European whortleberry (Vaccinium myrtillus);
      also, its edible bluish black fruit.
      [1913 Webster]

            There pinch the maids as blue as bilberry. --Shak.
      [1913 Webster]

   2. (Bot.) Any similar plant or its fruit; esp., in America,
      the species Vaccinium myrtilloides, Vaccinium
      c[ae]spitosum and Vaccinium uliginosum.
      [1913 Webster]