habitual \ha*bit"ual\ (?; 135), a. [cf. f. habituel, ll. habituals. see habit, n.] 1. formed or acquired by habit or use. an habitual knowledge of certain rules and maxims. 2. according to habit; established by habit; customary; constant; as, the habiual practice of sin. it is the distinguishing mark of habitual piety to be grateful for the most common and ordinary blessings.