The Collaborative International Dictionary of English v.0.48:

Imitate \Im"i*tate\, v. t. [imp. & p. p. Imitated; p. pr. &
   vb. n. Imitating.] [L. imitatus, p. p. of imitari to
   imitate; of unknown origin. Cf. Image.]
   1. To follow as a pattern, model, or example; to copy or
      strive to copy, in acts, manners etc.
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            Despise wealth and imitate a dog.     --Cowlay.
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   2. To produce a semblance or likeness of, in form, character,
      color, qualities, conduct, manners, and the like; to
      counterfeit; to copy.
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            A place picked out by choice of best alive
            The Nature's work by art can imitate. --Spenser.
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            This hand appeared a shining sword to weild,
            And that sustained an imitated shield. --Dryden.
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   3. (Biol.) To resemble (another species of animal, or a
      plant, or inanimate object) in form, color, ornamentation,
      or instinctive habits, so as to derive an advantage
      thereby; sa, when a harmless snake imitates a venomous one
      in color and manner, or when an odorless insect imitates,
      in color, one having secretion offensive to birds.
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WordNet (r) 3.0 (2006):

imitate
    v 1: reproduce someone's behavior or looks; "The mime imitated
         the passers-by"; "Children often copy their parents or
         older siblings" [syn: imitate, copy, simulate]
    2: appear like, as in behavior or appearance; "Life imitate art"
    3: make a reproduction or copy of