Synonyms of immemorial in English:

immemorial


See US English definition of immemorial

See UK English definition of immemorial

See Spanish definition of inmemorial

adjective

1‘an immemorial custom’

SYNONYMS
ancient, old, very old, age-old, antediluvian, timeless, dateless, archaic, long-standing, long-lived, time-worn, time-honoured
ancestral, traditional, atavistic
of yore, rooted in the past
ANTONYMS

recent