Source : Webster's Revised Unabridged Dictionary (1913)

Intoxicant \In*tox"i*cant\, n.
   That which intoxicates; an intoxicating agent; as, alcohol,
   opium, and laughing gas are intoxicants.

Source : WordNet®

intoxicant
     adj : able to intoxicate [syn: {intoxicating}]
     n 1: a liquor or brew containing alcohol as the active agent;
          "alcohol (or drink) ruined him" [syn: {alcohol}, {alcoholic
          beverage}, {inebriant}]
     2: a drug that can produce a state of intoxication