Source : Webster's Revised Unabridged Dictionary (1913)

Potion \Po"tion\, n. [L. potio, from potare to drink: cf. F.
   potion. See {Poison}.]
   A draught; a dose; usually, a draught or dose of a liquid
   medicine. --Shak.

Potion \Po"tion\, v. t.
   To drug. [Obs.] --Speed.

Source : WordNet®

potion
     n : a medicinal or magical or poisonous beverage