or ae·on

[ee-uh n, ee-on]


an indefinitely long period of time; age.
the largest division of geologic time, comprising two or more eras.
Astronomy. one billion years.

Origin of eon

see origin at aeon
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for eons

ages, aeon

Examples from the Web for eons

Contemporary Examples of eons

Historical Examples of eons

  • As China was for centuries, so for eons we of this earth have been isolated.

    The Fire People

    Ray Cummings

  • At last, after eons, they reached the corner of her own yard.


    Dana Gatlin

  • Presently, after eons it seemed, she desperately evoked a small, jerky voice.


    Dana Gatlin

  • The six days of Creation were six eons or geological periods.

  • After eons and eons of time the band played "Home, Sweet Home."


    Alice Hegan Rice

British Dictionary definitions for eons



the usual US spelling of aeon
geology the longest division of geological time, comprising two or more eras
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for eons



1640s, from Latin aeon, from Greek aion "age, vital force, a period of existence, lifetime, generation;" in plural, "eternity," from PIE root *aiw- "vital force, life, long life, eternity" (cf. Sanskrit ayu "life," Avestan ayu "age," Latin aevum "space of time, eternity," Gothic aiws "age, eternity," Old Norse ævi "lifetime," German ewig "everlasting," Old English a "ever, always").

Online Etymology Dictionary, © 2010 Douglas Harper

eons in Science



The longest division of geologic time, containing two or more eras.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.