epi·​phe·​nom·​e·​non ˌe-pi-fi-ˈnä-mə-ˌnän How to pronounce epiphenomenon (audio)
plural epiphenomena ˌe-pi-fi-ˈnä-mə-ˌnä How to pronounce epiphenomenon (audio)
: a secondary phenomenon accompanying another and caused by it
specifically : a secondary mental phenomenon that is caused by and accompanies a physical phenomenon but has no causal influence itself

Examples of epiphenomenon in a Sentence

Recent Examples on the Web There is this epiphenomenon that represents something much more deeply, structurally wrong in the American way of life. Katherine J. Wu, The Atlantic, 4 Aug. 2022 But if corporate climate action is partially an epiphenomenon of the labor market, then even a widespread conservative regime is unlikely to fully undermine it. Robinson Meyer, The Atlantic, 29 June 2022 Dreams, in other words, were just a neurological epiphenomenon left over from the meaningful parts of sleep — a side effect, an accident of biology, much like the way an incandescent light bulb designed to create light also happens to put out heat. New York Times, 3 Nov. 2021 Physicists, notably Eugene Wigner and John Wheeler, have speculated that consciousness, far from being a mere epiphenomenon of matter, is an essential component of reality. John Horgan, Scientific American, 27 Sep. 2021 Life, according to Crick, was an epiphenomenon of physics and chemistry — complex, yes, but still explicable in molecular terms. New York Times, 24 Mar. 2021 Knowland is not an epiphenomenon of cancel culture writ large, a hapless victim of the times. Cameron Hilditch, National Review, 4 Dec. 2020 The new conspiracism is more than simply an offshoot or epiphenomenon of other forces such as authoritarianism or strident populism. N.c., The Economist, 12 Aug. 2019 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'epiphenomenon.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from New Latin epiphenomen, epiphaenomenon, from epi- epi- + phenomenon, phaenomenon phenomenon

First Known Use

circa 1706, in the meaning defined above

Time Traveler
The first known use of epiphenomenon was circa 1706

Dictionary Entries Near epiphenomenon

Cite this Entry

“Epiphenomenon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epiphenomenon. Accessed 9 Dec. 2023.

Medical Definition


epi·​phe·​nom·​e·​non ˌep-i-fə-ˈnäm-ə-ˌnän, -nən How to pronounce epiphenomenon (audio)
: an accidental or accessory event or process occurring in the course of a disease but not necessarily related to that disease
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!