Source : Webster's Revised Unabridged Dictionary (1913)

Inveterate \In*vet"er*ate\, v. t.
   To fix and settle by long continuance. [Obs.] --Bacon.

Inveterate \In*vet"er*ate\, a. [L. inveteratus, p. p. of
   inveterare to render old; pref. in- in + vetus, veteris, old.
   See {Veteran}.]
   1. Old; long-established. [Obs.]

            It is an inveterate and received opinion. --Bacon.

   2. Firmly established by long continuance; obstinate;
      deep-rooted; of long standing; as, an inveterate disease;
      an inveterate abuse.

            Heal the inveterate canker of one wound. --Shak.

   3. Having habits fixed by long continuance; confirmed;
      habitual; as, an inveterate idler or smoker.

   4. Malignant; virulent; spiteful. --H. Brooke.

Source : WordNet®

inveterate
     adj : having a habit of long standing; "a chronic smoker" [syn: {chronic},
            {confirmed}, {habitual}, {inveterate(a)}]