immemorial

UK: /ˌɪmɪˈmɔːriəl/

US: /ˌɪməˈmɔriəl/

US: (im′ə môr′ē əl, -mōr′-)

WordReference Random House Learner's Dictionary of American English © 2025

im•me•mo•ri•al /ˌɪməˈmɔriəl/   adj. 

1. from time immemorial, from a period of time extending back beyond memory:
   From time immemorial these mountains have stood.

im•me•mo•ri•al•ly, adv. See -mem-.

WordReference Random House Unabridged Dictionary of American English © 2025

im•me•mo•ri•al  (im′ə môr′ē əl, -mōr′-), adj. 

1. extending back beyond memory, record, or knowledge:
   from time immemorial.

• Medieval Latin immemoriālis. See im-², memorial
• 1595–1605

im′me•mo′ri•al•ly, adv. 
Synonyms

timeless, ancient, ageless, olden.

Collins Concise English Dictionary © HarperCollins Publishers::

immemorial / ˌɪmɪˈmɔːrɪəl/ adjective

1. originating in the distant past; ancient (postpositive in the phrase time immemorial)

Etymology: 17th Century: from Medieval Latin immemoriālis, from Latin im- (not) + memoria memory

ˌimmeˈmorially adverb