Source : Webster's Revised Unabridged Dictionary (1913)

Mentha \Men"tha\, n. [L. See {Mint} the plant.] (Bot.)
   A widely distributed genus of fragrant herbs, including the
   peppermint, spearmint, etc. The plants have small flowers,
   usually arranged in dense axillary clusters.

Menthol \Men"thol\, n. [Mentha + -ol.] (Chem.)
   A white, crystalline, aromatic substance resembling camphor,
   extracted from oil of peppermint ({Mentha}); -- called also
   {mint camphor} or {peppermint camphor}.

Source : WordNet®

Mentha
     n : mint plants [syn: {genus Mentha}]