1. 
[syn: white hellebore, American hellebore, Indian poke, bugbane, Veratrum viride]
2.  a plant of the genus Cimicifuga having flowers in long racemes or panicles reported to be distasteful to insects; 
The Collaborative International Dictionary of English v.0.48:
Bugbane \Bug"bane`\, n. (Bot.)
   A perennial white-flowered herb of the order
   Ranunculace[ae] and genus Cimiciguga; bugwort. There are
   several species.
   [1913 Webster]
WordNet (r) 3.0 (2006):
bugbane
    n 1: North American plant having large leaves and yellowish
         green flowers growing in racemes; yields a toxic alkaloid
         used medicinally [syn: white hellebore, American
         hellebore, Indian poke, bugbane, Veratrum viride]
    2: a plant of the genus Cimicifuga having flowers in long
       racemes or panicles reported to be distasteful to insects