The Collaborative International Dictionary of English v.0.48:

Asarabacca \As`a*ra*bac"ca\, n. [L. asarum + bacca a berry. See
   Asarone.] (Bot.)
   An acrid herbaceous plant (Asarum Europ[ae]um), the leaves
   and roots of which are emetic and cathartic. It is
   principally used in cephalic snuffs.
   [1913 Webster]

WordNet (r) 3.0 (2006):

asarabacca
    n 1: thick creeping evergreen herb of western Europe [syn:
         asarabacca, Asarum europaeum]