The Collaborative International Dictionary of English v.0.48:

Lablab \Lab"lab\ (l[a^]b"l[a^]b), n. (Bot.)
   an East Indian name for several twining leguminous plants
   related to the bean, but commonly applied to the hyacinth
   bean (Dolichos Lablab).
   [1913 Webster]

WordNet (r) 3.0 (2006):

Lablab
    n 1: one species: hyacinth bean [syn: Lablab, genus Lablab]