inveterate

inveterate \in-VET-uh-rut\ adjective
1 : firmly established by long persistence
*2 : confirmed in a habit : habitual

Example sentence: Since Ernie is an inveterate liar, we naturally didn't believe him when he told us he'd met the movie star.

Did you know? Like "veteran," "inveterate" ultimately comes from Latin "vetus," which means "old," and which led to the Latin verb "inveterare" ("to age"). That verb in turn gave rise eventually to the adjective "inveteratus," the direct source of our adjective "inveterate" (in use since the 14th century). In the past, "inveterate" has meant "long-standing" or simply "old." For example, one 16th-century writer warned of "Those great Flyes which in the springe time of the yeare creepe out of inveterate walls." Today, "inveterate" most often applies to a habit, attitude, or feeling of such long existence that it is practically ineradicable or unalterable.