[ ep-uhk or, especially British, ee-pok ]
See synonyms for epoch on Thesaurus.com
  1. a particular period of time marked by distinctive features, events, etc.: The treaty ushered in an epoch of peace and good will.

  2. the beginning of a distinctive period in the history of anything: The splitting of the atom marked an epoch in scientific discovery.

  1. 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.

  2. Geology. any of several divisions of a geologic period during which a geologic series is formed.: Compare age (def. 12).

  3. Astronomy.

    • 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.

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

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

Origin of epoch

1605–15; <New Latin epocha<Greek epochḗ pause, check, fixed time, equivalent to ep-ep- + och- (variant stem of échein to have) + noun suffix

synonym study For epoch

1. See age.

Other words for epoch

Other words from epoch

  • sub·ep·och, noun
  • su·per·ep·och, noun

Words that may be confused with epoch

Words Nearby epoch

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use epoch in a sentence

British Dictionary definitions for epoch


/ (ˈiːpɒk) /

  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

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

  2. geology a unit of geological time within a period during which a series of rocks is formed: the Pleistocene epoch

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

Origin of epoch

C17: from New Latin epocha, from Greek epokhē cessation; related to ekhein to hold, have

Derived forms of epoch

  • epochal (ˈɛpˌɒkəl), adjective
  • epochally, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for epoch


[ ĕpək, ēpŏk′ ]

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

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.