Todays word of the day comes from THE DIARY OF A BOOKSELLER by Shaun Bythell.
INVETERATE -
ADJECTIVE having a particular habit, activity, or interest that is long-established and unlikely to change. "an inveterate gambler" synonyms: ingrained · deep-seated · deep-rooted · deep-set · entrenched · established · long-established · congenital · ineradicable · incurable · irredeemable (of a feeling or habit) long-established and unlikely to change. "his inveterate hostility to what he considered to be the ‘reactionary’ powers" synonyms: confirmed · hardened · chronic · hard-core · incorrigible · habitual · addicted · compulsive · obsessive · obsessional · pathological · hooked · staunch · steadfast · committed · devoted · dedicated · deep-dyed · dyed-in-the-wool · thorough · thoroughgoing · out and out · diehard · long-standing
ORIGIN late Middle English (referring to disease, in the sense ‘of long standing, chronic’): from Latin inveteratus ‘made old’, past participle of inveterare (based on vetus, veter- ‘old’).