eon

noun

ˈē-ən  ˈē-ˌän 

variants or chiefly British aeon

1

: an immeasurably or indefinitely long period of time : age

I haven't seen him in eons.

2

a

: a very large division of geologic time usually longer than an era

the Archean eon

b

: a unit of geologic time equal to one billion years

Examples of eon in a Sentence

Recent Examples on the Web

Presented with the premise that a sprinter will never run 100 meters in, say, five seconds, Lyles wondered what humans could accomplish an eon from now. —Emily Giambalvo, Washington Post, 26 July 2024

The Cloud’s residents may be a reason why life ignited on Earth; crashing on our planet eons ago, these ice bodies may have supplied at least some of the water that all life requires. —James Wray, Discover Magazine, 18 Oct. 2024

Working in a genre that already feels eons ahead, DJ Travella somehow blasts singeli even further into hyperdrive. —Pitchfork, 1 Oct. 2024

Here are steps to hire the right one For kids, that seems like eons away. —Winnie Sun, CNBC, 29 Sep. 2024

Word History

Etymology

borrowed from Late Latin aeōn "age (in the world's history), evil spirit (in Gnosticism)," borrowed from Greek aiṓn "lifetime, long period of time, age" — more at aye entry 3

First Known Use

circa 1642, in the meaning defined at sense 1

Kids Definition

eon

noun

ˈē-ən

1

: a very long period of time

2

a

: a very large division of geologic time usually longer than an era

b

: a unit of geologic time equal to one billion years