The Collaborative International Dictionary of English v.0.48:

Wood hyacinth \Wood hyacinth\
   A European squill (Scilla nonscripta) having a scape
   bearing a raceme of drooping blue, purple, white, or
   sometimes pink, bell-shaped flowers.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

wood hyacinth
    n 1: sometimes placed in genus Scilla [syn: wild hyacinth,
         wood hyacinth, bluebell, harebell, Hyacinthoides
         nonscripta, Scilla nonscripta]