Source : Webster's Revised Unabridged Dictionary (1913)

Vanillin \Va*nil"lin\, n. (Chem.)
   A white crystalline aldehyde having a burning taste and
   characteristic odor of vanilla. It is extracted from vanilla
   pods, and is also obtained by the decomposition of coniferin,
   and by the oxidation of eugenol.

Source : WordNet®

vanillin
     n : a crystalline compound found in vanilla beans and some
         balsam resins; used in perfumes and flavorings