poly·​pha·​sic ˌpä-lē-ˈfā-zik How to pronounce polyphasic (audio)
: consisting of two or more phases

Example Sentences

Recent Examples on the Web Simon says newborn infants will sleep roughly 18 hours a day in multiple bouts, which is called polyphasic sleep. Carl Engelking, Discover Magazine, 6 Jan. 2017 The fast, as well as Massaro encouraging his followers to engage in polyphasic sleep, a technique in which people sleep for just a few hours at a time, were framed as part of the pathway to enlightenment. Ej Dickson, Rolling Stone, 18 Apr. 2022 Some literature and research suggests that humans are naturally polyphasic sleepers. Jamie Ducharme, Time, 30 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'polyphasic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use

1922, in the meaning defined above

Time Traveler
The first known use of polyphasic was in 1922

Dictionary Entries Near polyphasic

Cite this Entry

“Polyphasic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polyphasic. Accessed 2 Feb. 2023.

Medical Definition


poly·​pha·​sic -ˈfā-zik How to pronounce polyphasic (audio)
: of, relating to, or having more than one phase
polyphasic evoked potentials
compare diphasic sense b, monophasic sense 1
: having several periods of activity interrupted by intervening periods of rest in each 24 hours
an infant is essentially polyphasic
Last Updated: - Updated example sentences
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