bio·​rhythm ˈbī-ō-ˌri-t͟həm How to pronounce biorhythm (audio)
: an innately determined rhythmic biological process or function (such as sleep behavior)
also : the internal mechanism that determines such a process or function
biorhythmic adjective

Examples of biorhythm in a Sentence

Recent Examples on the Web Its tone remains a bit distant, its pace a few clicks under what seems like the natural biorhythm of the play. Sara Holdren, Vulture, 16 Nov. 2023 Wearing black shorts, a blue undershirt and a black harness over his chest that tracked biorhythms, Dante Moore moved his arms rhythmically while standing alone on one corner of the field about 15 minutes before the start of UCLA’s training camp. Houston Mitchell, Los Angeles Times, 3 Aug. 2023 My son has a set biorhythm, and no arbitrary daylight saving law is going to shift it. Rachel Meyer,, 22 Nov. 2019 The biorhythm lasts for one day in rats; four days in macaques; five days in sheep; and six to 12 days in humans. Quanta Magazine, 13 Dec. 2016 Perhaps not coincidentally, these are the only two physiological features that Bromage found to directly correlate with the length of the new biorhythm. Quanta Magazine, 13 Dec. 2016 Deutsche Lufthansa AG last year began using 24 different light settings on its Airbus A350-900 planes to help manage passenger biorhythms during long haul flights. Robert Wall, WSJ, 24 Mar. 2018 See More

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

Word History

First Known Use

1913, in the meaning defined above

Time Traveler
The first known use of biorhythm was in 1913

Dictionary Entries Near biorhythm

Cite this Entry

“Biorhythm.” Dictionary, Merriam-Webster, Accessed 3 Dec. 2023.

Medical Definition


bio·​rhythm ˈbī-ō-ˌrit͟h-əm How to pronounce biorhythm (audio)
: an innately determined rhythmic biological process or function (as sleep behavior)
also : an innate rhythmic determiner of such a process or function
biorhythmic adjective
biorhythmicity noun
plural biorhythmicities

More from Merriam-Webster on biorhythm

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