eon

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For more information on eon, visit Britannica.com.

geology The largest unit of the geochronologic scale, being often thought of as a billion (10⁹) years (and proposed by Gamow to be exactly that
[Gamow G. Nature Vol. 219, 765 (1968)]). Deriving etymologically from ‘life’, eon, in the form of the current eon (the Phanerozoic, lasting about 570 million years), encompassed the whole fossil record when it was introduced. Preceding time was lumped together as the undifferentiated lifeless ‘pre-Cambrian’ eon of 4 billion years. Now that too is seen as including life, and is divided. The next smaller unit is era.

noun

A long time: eternity, long¹, year (used in plural). Informal age (used in plural), blue moon. Idioms: forever and a day, forever and ever, month of Sundays. See time.

• Periods of Time - eon: extremely long period of time; aeon

Dansk (Danish)
n. - uendeligt tidsrum, evighed

Nederlands (Dutch)
(een) eeuwigheid, eon, 1 miljard jaar

Français (French)
n. - éternité, temps infini, période incommensurable

Deutsch (German)
n. - Äon (Zeitraum, Weltalter)

Ελληνική (Greek)
n. - αιώνας

Italiano (Italian)
era

Português (Portuguese)
n. - eternidade (f)

Русский (Russian)
эра, вечность

Español (Spanish)
n. - eón

Svenska (Swedish)
n. - tidsålder, evighet

中文（简体）(Chinese (Simplified))
永世, 十亿年期, 万古

中文（繁體）(Chinese (Traditional))
n. - 永世, 十億年期, 萬古

한국어 (Korean)
n. - 영구

日本語 (Japanese)
n. - 測り知れない長年月, エオン

العربيه (Arabic)
‏(الاسم) دهر, فتره لا نهائيه‏

עברית (Hebrew)
n. - ‮עידן, תקופה‬

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