Source : Webster's Revised Unabridged Dictionary (1913)

Cymene \Cy"mene\ (s?"m?n), n. (Chem.)
   A colorless, liquid, combustible hydrocarbon,
   {CH3.C6H4.C3H7}, of pleasant odor, obtained from oil of
   cumin, oil of caraway, carvacrol, camphor, etc.; -- called
   also {paracymene}, and formerly {camphogen}.

Source : WordNet®

cymene
     n : any of three isotopes of a colorless aromatic liquid
         hydrocarbon occuring in the volatile oil of cumin and
         thyme and used in the manufacture of synthetic resins