\ ˈē-ən How to pronounce eon (audio) , ˈē-ˌän How to pronounce eon (audio) \
variants: or chiefly British

Definition of eon

1 : an immeasurably or indefinitely long period of time : age I haven't seen him in eons.
2a : 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 But after eons of evolutionary experimentation, some lineages peaced out of the terrestrial world and embraced a full-time life at sea again. Becky Ferreira, New York Times, "When Crocodiles Once Dived Like Dolphins and Whales," 20 Apr. 2020 Minimalism had recently gone super-mainstream after decades—or, by some definitions, eons—of insurgency. Spencer Kornhaber, The Atlantic, "The Pandemic Has Made a Mockery of Minimalism," 23 Apr. 2020 Radio silence For two hours – and what felt like eons to those trying to figure out what was happening – this mad scramble continued with no update from DeWine, LaRose or any other state or local official. Andrew J. Tobias, cleveland, "Inside the chaos that engulfed Ohio’s postponed primary election," 17 Mar. 2020 The legislature’s end was five days late but seemed an eon from its opening in January. Laura Vozzella, Washington Post, "Virginia Democrats finish historic session under cloud of the coronavirus and economic uncertainty," 12 Mar. 2020 Santa Anita review Poster Girl won Thursday’s feature, a $53,000 allowance/optional claimer for fillies and mares going a mil eon the turf. Los Angeles Times, "Racing! Here are the bets you want at Santa Anita," 4 Oct. 2019 Yes, hairstylist Duffy may have swept up her brunette lengths into an equal parts voluminous and sculptural bouffant with sharp, zig-zagged fringe, eons of teasing and hairspray administered in the process. Lauren Valenti, Vogue, "Bella Hadid Bleaches Her Brows for the Haider Ackermann Runway," 29 Feb. 2020 Ohio State was eons better as a team, but the market price dictated that betting against them was profitable. Christopher Smith, al, "Expect Auburn to cover the Iron Bowl spread," 25 Nov. 2019 Xana was a leader who welcomed any idea from any person, someone whose mind could be changed on most things, who respected talent and generosity more than eons of experience or buckets of self-assurance. Kira Bindrim, Quartz, "Remembering Xana Antunes, a mentor to just about everyone she met," 28 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'eon.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of eon

circa 1642, in the meaning defined at sense 1

History and Etymology for eon

Latin, from Greek aiōn — more at aye entry 3

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Time Traveler for eon

Time Traveler

The first known use of eon was circa 1642

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Statistics for eon

Last Updated

13 May 2020

Cite this Entry

“Eon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/eon. Accessed 26 May. 2020.

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More Definitions for eon


How to pronounce eon (audio) How to pronounce eon (audio)

English Language Learners Definition of eon

: a very long period of time


Kids Definition of eon

variant of

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More from Merriam-Webster on eon

Rhyming Dictionary: Words that rhyme with eon

Spanish Central: Translation of eon

Nglish: Translation of eon for Spanish Speakers

Britannica English: Translation of eon for Arabic Speakers

Britannica.com: Encyclopedia article about eon

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