inveterate (adj.)youdaoicibaDictYouDict[inveterate 词源字典]
late 14c., from Latin inveteratus "of long standing, chronic," past participle of inveterare "become old in," from in- "in, into" (see in- (2)) + veterare "to make old," from vetus (genitive veteris) "old" (see veteran).[inveterate etymology, inveterate origin, 英语词源]