Synonyms and Antonyms of immemorial
- the immemorial Alps, where once Hannibal's army marched
antiquated, archaic, archaistic, dated, fusty, geriatric, medieval (also mediaeval), moldy, Noachian, obsolete, outmoded, out-of-date, passé
old-fashioned, old-time, old-world, retro, vintage
durable, enduring, lasting, long-lived, permanent
ageless, hallowed, time-honored, timeless, time-tested, timeworn, traditional, tried, tried-and-true
prehistoric (also prehistorical), primeval, primordial