epoch

American  

[ep-uhk, ee-pok] / ˈɛp ək, ˈi pɒk /

noun

• epochs
  plural

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 /

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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Synonym Usage

See age.

Other Word Forms

Derived Forms

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

Inflected Forms

Nouns

• epochs
  plural

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

See Examples For:

epoch epochs

Today America is in the midst of the greatest epoch of wealth creation the world has ever known.

From The Wall Street Journal ● Aug. 2, 2026

These newly discovered quasars come from a critical period known as the epoch of reionization, when the first stars and galaxies transformed the early universe by ionizing the neutral hydrogen gas that once filled space.

From Science Daily ● Jul. 9, 2026

But for Icelanders, whose connection to glaciers is ancient and mythic, our human epoch has become an extended hospice for the landscape of their lives.

From Los Angeles Times ● Jun. 5, 2026

So how should investors position themselves for this new, problematic epoch?

From MarketWatch ● Apr. 10, 2026

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

From "1491" by Charles C. Mann

“Every time we have one of these technical epochs, it puts pressure on the infrastructure, but none of us have ever seen it this dramatic,” said Casado.

From The Wall Street Journal ● Aug. 28, 2026

Disney Chairman James Gorman said in an interview that Iger’s nearly 20 years in power is framed by two epochs: “Bob 1” and “Bob 2.”

From Los Angeles Times ● Feb. 4, 2026

He said Traoré was "offering an alternative, and re-capturing the spirit of two historic epochs":

From BBC ● May 11, 2025

Since the paleoecologists focus on Deep Time, or epochs from tens of millions of years ago, they call their ensembles DeepMIPs.

From Salon ● Feb. 17, 2025

These—oral culture, written culture, the culture of print—these have always been considered the great epochs of man.

From "Feed" by M.T. Anderson