aeon

Từ điển Oxford Advanced Learner 8th

aeon [aeon aeons] (BrE) (also eon NAmE, BrE)BrE [ˈiːən] NAmE [ˈiːən] noun
1. (formal)an extremely long period of time; thousands of years
•Only yesterday — and it seemed aeons ago, not just a few hours — he had been a happily married man.
2. (geology)a major division of time, divided into ↑eras
•aeons of geological history
See also: ↑eon

Word Origin:
mid 17th cent.: via ecclesiastical Latin from Greek aiōn ‘age’.

Example Bank:
•These hills have been worn down over aeons of geological time.