epoch

noun

ep·​och ˈe-pək 

ˈe-ˌpäk,

US also and British usually

ˈē-ˌpäk 

1

a

: an event or a time marked by an event that begins a new period or development

b

: a memorable event or date

2

a

: an extended period of time usually characterized by a distinctive development or by a memorable series of events

b

: a division of geologic time less than a period and greater than an age

3

: an instant of time or a date selected as a point of reference (as in astronomy)

Did you know?

Epoch comes to us, via Medieval Latin, from Greek epochē, meaning "cessation" or "fixed point." "Epochē," in turn, comes from the Greek verb epechein, meaning "to pause" or "to hold back." When "epoch" was first borrowed into English, it referred to the fixed point used to mark the beginning of a system of chronology. That sense is now obsolete, but today "epoch" is used in some fields (such as astronomy) with the meaning "an instant of time or a date selected as a point of reference." The "an event or a time that begins a new period or development" sense first appeared in print in the early 17th century, and "epoch" has been applied to defining moments or periods of time ever since.

Synonyms

• age
• day
• era
• period
• time

Choose the Right Synonym for epoch

period, epoch, era, age mean a division of time.

period may designate an extent of time of any length.

periods of economic prosperity

epoch applies to a period begun or set off by some significant or striking quality, change, or series of events.

the steam engine marked a new epoch in industry

era suggests a period of history marked by a new or distinct order of things.

the era of global communications

age is used frequently of a fairly definite period dominated by a prominent figure or feature.

the age of Samuel Johnson

Examples of epoch in a Sentence

The Civil War era was an epoch in 19th-century U.S. history.

The development of the steam engine marked an important epoch in the history of industry.

Recent Examples on the Web

In the epoch of artificial intelligence (AI), the demand for real-time decision-making and data-processing applications is rapidly increasing. —Cristian Randieri, Forbes, 22 Nov. 2024

This revelation constrains modern understanding of the Pleistocene sea level fluctuations during an epoch of lower carbon dioxide concentrations, the cyclic glaciation and deglaciation periods, ecosystem recovery, and the transition between warming and cooling periods. —Carly Miller, Forbes, 27 Sep. 2024

Written and directed by Mamoru Oshii and based on the manga by Masamune Shirow, the film sits at the center of a Venn diagram of several cultural epochs. —Dan Schindel, Vulture, 21 June 2024

During the epoch starting in 2032, more than 99% of the bitcoin supply will have been issued. —Liam Wright, Forbes, 30 Sep. 2024

Word History

Etymology

Medieval Latin epocha, from Greek epochē cessation, fixed point, from epechein to pause, hold back, from epi- + echein to hold — more at scheme entry 1

First Known Use

1614, in the meaning defined at sense 1a

Phrases Containing epoch

• epoch-making

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Kids Definition

epoch

noun

ep·​och ˈep-ək  -ˌäk 

 also  ˈē-ˌpäk

1

: an event or a time that begins a new period of development

2

: a memorable event, date, or period

3

: a division of geologic time less than a period and greater than an age

epochal

-əl

adjective

epochally

-ə-lē

adverb