The Collaborative International Dictionary of English v.0.48:

Naturalize \Nat"u*ral*ize\ (?; 135), v. t. [imp. & p. p.
   Naturalized; p. pr. & vb. n. Naturalizing.] [Cf. F.
   naturaliser. See Natural.]
   1. To make natural; as, custom naturalizes labor or study.
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   2. To confer the rights and privileges of a native subject or
      citizen on; to make as if native; to adopt, as a foreigner
      into a nation or state, and place in the condition of a
      native subject.
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   3. To receive or adopt as native, natural, or vernacular; to
      make one's own; as, to naturalize foreign words.
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   4. To adapt; to accustom; to habituate; to acclimate; to
      cause to grow as under natural conditions.
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            Its wearer suggested that pears and peaches might
            yet be naturalized in the New England climate.
                                                  --Hawthorne.
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