inveterate
🇺🇸
/ɪnˈvetərət/
🇬🇧
/ɪnˈvetərət/
someone who always does something and probably won't stop
She's an inveterate reader, always found with a book in hand.
feeling or doing something for a long time and not likely to change
His inveterate optimism keeps him going, even in tough times.