Source : Webster's Revised Unabridged Dictionary (1913)

Cannabin \Can"na*bin\, n. (Chem.)
   A poisonous resin extracted from hemp ({Cannabis sativa},
   variety Indica). The narcotic effects of hasheesh are due to
   this resin.

Source : WordNet®

cannabin
     n : a resin obtained from the hemp plant; thought to be the
         active narcotic agent in marijuana [syn: {cannabis resin}]