ep·​och | \ ˈe-pək How to pronounce epoch (audio) , ˈe-ˌpäk, US also and British usually ˈē-ˌpäk How to pronounce epoch (audio) \

Definition of epoch

1a : an event or a time marked by an event that begins a new period or development
b : a memorable event or date
2a : 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)

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Synonyms for epoch


age, day, era, period, time

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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

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.

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

Earlier this year, scientists suggested that the Anthropoecene, a geologic epoch defined by ways humans have altered Earth, began in 1950. Ashley Strickland, CNN, "Humans have been impacting Earth for thousands of years, study says," 29 Aug. 2019 From about 15,000 to 10,000 years ago — the end of the Pleistocene epoch — a warming climate, the increasing encroachment of humans, or some combination of both led to a massive extinction of some of North America’s largest mammals. Stephanie De Marco, Los Angeles Times, "Bones pulled from the La Brea Tar Pits show the perils of being a picky eater," 26 Aug. 2019 As curious as these objects may be, scientists already point to the appearance of plastics in this form as a signpost for the beginning of the Anthropocene epoch, an age in which humanity’s imprint on the natural world is indisputable. Daniel Wolfe, Quartz, "How plastic turns into rocks and ends up on our beaches," 8 Aug. 2019 In the larger, more mature galaxies of this early epoch, there were more supernovae, and dust from these stellar explosions absorbed most of the UV light. Adrian Cho, Science | AAAS, "Galaxy hunters spot hidden giants in the early universe," 7 Aug. 2019 Art museums now seem to feel that topical relevance is somehow served by appending recent art to exhibitions otherwise anchored in a historical epoch. Los Angeles Times, "Review: Unicorns are just one of the wild rides in the Getty’s marvelous ‘Book of Beasts’," 23 July 2019 Despite being large and in charge, Simbakubwa did not make it and even its relatives were extinct by the end of the Miocene epoch, roughly five million years ago. Matthew Borths, National Geographic, "This new species of ancient carnivore was bigger than a polar bear," 18 Apr. 2019 After protracted slumber in Earth’s icy fringes, bacteria, moss and nematodes are awakening in a new geologic epoch. Daniel Ackerman, Anchorage Daily News, "Ancient life awakens amid thawing ice caps and permafrost," 8 July 2019 The epoch contains far more data than the CMB, which only records a brief moment in cosmic time. Daniel Clery, Science | AAAS, "Could humanity’s return to the moon spark a new age of lunar telescopes?," 18 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'epoch.' 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 epoch

1614, in the meaning defined at sense 1a

History and Etymology for epoch

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

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Last Updated

17 Sep 2019

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The first known use of epoch was in 1614

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English Language Learners Definition of epoch

: a period of time that is very important in history


ep·​och | \ ˈe-pək How to pronounce epoch (audio) \

Kids Definition of epoch

: a period that is important or memorable

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More from Merriam-Webster on epoch

Rhyming Dictionary: Words that rhyme with epoch

Thesaurus: All synonyms and antonyms for epoch

Spanish Central: Translation of epoch

Nglish: Translation of epoch for Spanish Speakers

Britannica English: Translation of epoch for Arabic Speakers

Britannica.com: Encyclopedia article about epoch

Comments on epoch

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to spread over or through

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