Source : Webster's Revised Unabridged Dictionary (1913)

Adulterate \A*dul"ter*ate\, v. t. [imp. & p. p. {Adulterated};
   p. pr. & vb. n. {Adulterating}.] [L. adulteratus, p. p. of
   adulterare, fr. adulter adulterer, prob. fr. ad + alter
   other, properly one who approaches another on account of
   unlawful love. Cf. {Advoutry}.]
   1. To defile by adultery. [Obs.] --Milton.

   2. To corrupt, debase, or make impure by an admixture of a
      foreign or a baser substance; as, to adulterate food,
      drink, drugs, coin, etc.

            The present war has . . . adulterated our tongue
            with strange words.                   --Spectator.

   Syn: To corrupt; defile; debase; contaminate; vitiate;
        sophisticate.

Adulterate \A*dul"ter*ate\, v. i.
   To commit adultery. [Obs.]

Adulterate \A*dul"ter*ate\, a.
   1. Tainted with adultery.

   2. Debased by the admixture of a foreign substance;
      adulterated; spurious. -- {A*dul"ter*ate*ly}, adv. --
      {A*dul"ter*ate*ness}, n.

Source : WordNet®

adulterate
     adj : mixed with impurities [syn: {adulterated}, {debased}]

adulterate
     v : corrupt, debase, or make impure by adding a foreign or
         inferior substance; often by replacing valuable
         ingredients with inferior ones; "adulterate liquor" [syn:
          {stretch}, {dilute}, {debase}]