1 (of a person) confirmed in an (esp. undesirable) habit etc. (an inveterate gambler).
2 a (of a habit etc.) long-established. b (of an activity, esp. an undesirable one) habitual.
Derivatives:
inveteracy n. inveterately adv.
Etymology: ME f. L inveterare inveterat- make old (as IN-(2), vetus veteris old)
Useful english dictionary. 2012.