epoch

American  

[ep-uhk, ee-pok] / ˈɛp ək, ˈi pɒk /

noun

1. a particular period of time marked by distinctive features, events, etc..

   The treaty ushered in an epoch of peace and good will.

   Synonyms:

   time, era, date, age

2. the beginning of a distinctive period in the history of anything.

   The splitting of the atom marked an epoch in scientific discovery.

3. a point of time distinguished by a particular event or state of affairs; a memorable date.

   His coming of age was an epoch in his life.

4. Geology. any of several divisions of a geologic period during which a geologic series is formed.

5. Astronomy.

   1. an arbitrarily fixed instant of time or date, usually the beginning of a century or half century, used as a reference in giving the elements of a planetary orbit or the like.

   2. the mean longitude of a planet as seen from the sun at such an instant or date.

6. Physics. the displacement from zero at zero time of a body undergoing simple harmonic motion.

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epoch British  

/ ˈiːpɒk, ˈɛpˌɒkəl /

noun

1. a point in time beginning a new or distinctive period

   the invention of nuclear weapons marked an epoch in the history of warfare

2. a long period of time marked by some predominant or typical characteristic; era

3. astronomy a precise date to which information, such as coordinates, relating to a celestial body is referred

4. geology a unit of geological time within a period during which a series of rocks is formed

   the Pleistocene epoch

5. physics the displacement of an oscillating or vibrating body at zero time

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epoch Scientific  

/ ĕp′ək,ē′pŏk′ /

1. The shortest division of geologic time. An epoch is a subdivision of a period.

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Related Words

See age.

Other Word Forms

• epochal adjective
• epochally adverb
• subepoch noun
• superepoch noun

Etymology

Origin of epoch

First recorded in 1605–15; from New Latin epocha, from Greek epochḗ “pause, check, fixed time,” from ep- ep- + och- (variant stem of échein “to have, hold, keep”) + -ē, noun suffix

Explanation

An epoch is a period of time marked by certain characteristics: You might describe several peaceful decades in a nation's history as an epoch of peace. In geologic time, an epoch is a division of a period, and an age is a division of an epoch. Epoch can also refer to a distinct and important period of history, or an event that marks such a period: an epoch in the world of ballet, for example. The noun epoch is from New Latin epocha, from Greek epochē, "pause, check, fixed time."

Example Sentences

Charismatic and charming as ever, Gosling easily shoulders the job of being the only human onscreen for an epoch.

From Los Angeles Times • Mar. 18, 2026

I've been presenting television debates and radio phone-ins over five decades, stumbling from one epoch to the next.

From BBC • Mar. 7, 2026

Fundamental to Clark’s investment worldview is his conviction that “the era of capital abundance has ended” and global markets are adjusting towards a new epoch of capital scarcity.

From MarketWatch • Feb. 24, 2026

Enthusiasts of the Dutch and Flemish Golden Age will be delighted to learn of the more quotidian arts that rounded out this visually rich epoch: hand-wrought lace, calligraphy, botanical illustrations and more.

From The Wall Street Journal • Nov. 21, 2025

The Olmec were but the first of many societies that arose in Mesoamerica in this epoch.

From "1491" by Charles C. Mann