Source : Webster's Revised Unabridged Dictionary (1913)

Damiana \Da`mi*a"na\, n. [NL.; of uncertain origin.] (Med.)
   A Mexican drug, used as an aphrodisiac.

   Note: There are several varieties derived from different
         plants, esp. from a species of {Turnera} and from
         {Bigelovia veneta}. --Wood & Bache.