Other forms: eons
An eon is an immensely long period of time. Eons ago, over eons, an eon of waiting.
In geology it is exact: an eon is the largest division of time, and the current one has run for half a billion years. In ordinary speech it is a plural exaggeration, and eons ago means quite a while. Britain often spells it aeon.
1nouneonAn immensely long period of time.
“The mountains were shaped by wind and water over eons.”
eon is a period.
Also accepted in games: aeon
Greek aion means an age or a lifetime, from a root meaning vital force.
Proto-Indo-European
*h₂ey-
Ancient Greek
αἰών — age, era
Latin
aeon
English, today
eon
From Latin aeon, from Ancient Greek αἰών (“age, era”).
Etymology from Wiktionary, CC BY-SA