Inveterate is a formal word used to describe someone who is always or often doing something specified. For instance, a person could be an inveterate liar, or inveterate prankster. Inveterate can also mean “firmly established by long persistence,” as in “an inveterate tendency to overlook the obvious.”
She’s an inveterate traveler who constantly searches for flight deals to her next destination.
Carla’s inveterate optimism keeps her going during challenging times.
She’s an inveterate gambler and has lost more than she has ever won.