The Collaborative International Dictionary of English v.0.48:

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.]
   [1913 Webster]
   1. To defile by adultery. [Obs.] --Milton.
      [1913 Webster]

   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.
      [1913 Webster]

            The present war has . . . adulterated our tongue
            with strange words.                   --Spectator.
      [1913 Webster]

   Syn: To corrupt; defile; debase; contaminate; vitiate;
        sophisticate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

adulterated \adulterated\ adj.
   1. having been made impure by addition of inferior
      ingredients; -- said of substances or foods

   Note: used ususally of articles of commerce, dulted with less
         costly materials so as to enhance profit; -- usually
         imlying that the dilution is surreptitious and
         unethical

   Syn: adulterate, debased
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

adulterated
    adj 1: mixed with impurities [syn: adulterate, adulterated,
           debased]