The Collaborative International Dictionary of English v.0.48:

Habitual \Ha*bit"ual\ (h[.a]*b[i^]t"[-u]*al; 135), a. [Cf. F.
   habituel, LL. habitualis. See Habit, n.]
   1. Formed or acquired by habit or use.
      [1913 Webster]

            An habitual knowledge of certain rules and maxims.
                                                  --South.
      [1913 Webster]

   2. According to habit; established by habit; customary;
      constant; as, the habitual practice of sin.
      [1913 Webster]

            It is the distinguishing mark of habitual piety to
            be grateful for the most common and ordinary
            blessings.                            --Buckminster.

   Syn: Customary; accustomed; usual; common; wonted; ordinary;
        regular; familiar. -- Ha*bit"u*al*ly, adv. --
        Ha*bit"u*al*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

habitual
    adj 1: commonly used or practiced; usual; "his accustomed
           thoroughness"; "took his customary morning walk"; "his
           habitual comment"; "with her wonted candor" [syn:
           accustomed, customary, habitual, wonted(a)]