The Collaborative International Dictionary of English v.0.48:

Addict \Ad*dict"\, v. t. [imp. & p. p. Addicted; p. pr. & vb.
   n. Addicting.] [L. addictus, p. p. of addicere to adjudge,
   devote; ad + dicere to say. See Diction.]
   1. To apply habitually; to devote; to habituate; -- with to.
      "They addict themselves to the civil law." --Evelyn.
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            He is addicted to his study.          --Beau. & Fl.
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            That part of mankind that addict their minds to
            speculations.                         --Adventurer.
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            His genius addicted him to the study of antiquity.
                                                  --Fuller.
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            A man gross . . . and addicted to low company.
                                                  --Macaulay.
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   2. To adapt; to make suitable; to fit. [Obs.]
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            The land about is exceedingly addicted to wood, but
            the coldness of the place hinders the growth.
                                                  --Evelyn.
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   Syn: Addict, Devote, Consecrate, Dedicate. Addict was
        formerly used in a good sense; as, addicted to letters;
        but is now mostly employed in a bad sense or an
        indifferent one; as, addicted to vice; addicted to
        sensual indulgence. "Addicted to staying at home." --J.
        S. Mill. Devote is always taken in a good sense,
        expressing habitual earnestness in the pursuit of some
        favorite object; as, devoted to science. Consecrate and
        dedicate express devotion of a higher kind, involving
        religious sentiment; as, consecrated to the service of
        the church; dedicated to God.
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WordNet (r) 3.0 (2006):

addicted
    adj 1: compulsively or physiologically dependent on something
           habit-forming; "she is addicted to chocolate"; "addicted
           to cocaine" [ant: unaddicted]