adj. 25B6; adjective ANCIENT, (very) old, age-old, antediluvian, timeless, archaic, long-standing, time-worn, time-honoured; traditional; poetic/literary of yore.
IMMEMORIAL
Meaning of IMMEMORIAL in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012