Source : Webster's Revised Unabridged Dictionary (1913)

Bluebell \Blue"bell`\, n. (Bot.)
   (a) A plant of the genus {Campanula}, especially the
       {Campanula rotundifolia}, which bears blue bell-shaped
       flowers; the harebell.
   (b) A plant of the genus {Scilla} ({Scilla nutans}).

Source : WordNet®

bluebell
     n 1: sometimes placed in genus Scilla [syn: {wild hyacinth}, {wood
          hyacinth}, {harebell}, {Hyacinthoides nonscripta}, {Scilla
          nonscripta}]
     2: one of the most handsome prairie wildflowers laving large
        erect bell-shaped bluish flowers; of moist places in
        prairies and fields from eastern Colorado and Nebraska
        south to New Mexico and Texas [syn: {prairie gentian}, {tulip
        gentian}, {Eustoma grandiflorum}]
     3: perennial of northern hemisphere with slender stems and
        bell-shaped blue flowers [syn: {harebell}, {Campanula
        rotundifolia}]