• synonyms


[ee-uh n, ee-on]
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  1. (in Gnosticism) one of a class of powers or beings conceived as emanating from the Supreme Being and performing various functions in the operations of the universe.
  2. eon.
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Origin of aeon

1640–50; < Late Latin < Greek aiṓn space of time, age


or ae·on

[ee-uh n, ee-on]
  1. an indefinitely long period of time; age.
  2. the largest division of geologic time, comprising two or more eras.
  3. Astronomy. one billion years.
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Origin of eon

see origin at aeon
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words


Examples from the Web for aeon

Contemporary Examples

Historical Examples

  • It seemed as if he had reached sanctuary after an aeon of chaos.

    Garrison's Finish

    W. B. M. Ferguson

  • After what seemed an aeon, they saw that it was daylight outside.

  • When it was spent, they would rest for aeon, then stir again.

    Lewis Rand

    Mary Johnston

  • For a moment that had to Letty the air of an aeon, Godfrey stood peering.

    Mary Marston

    George MacDonald

  • Eight years have elapsed since that day and this writing—an aeon in this rapidly moving Republic of ours.

British Dictionary definitions for aeon


esp US eon

  1. an immeasurably long period of time; age
  2. a period of one thousand million years
  3. (often capital) gnosticism one of the powers emanating from the supreme being and culminating in the demiurge
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Word Origin

C17: from Greek aiōn an infinitely long time


  1. the usual US spelling of aeon
  2. geology the longest division of geological time, comprising two or more eras
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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 aeon


1640s; see eon.

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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").

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Online Etymology Dictionary, © 2010 Douglas Harper

aeon in Science


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