biological clock


: an inherent timing mechanism in a living system that is inferred to exist in order to explain the timing or periodicity of various behaviors and physiological states and processes

Examples of biological clock in a Sentence

Recent Examples on the Web So much for beating the biological clock, as promised by a multimillion-dollar industry that promoted its technologies in part as a way for women to avoid detrimental career disruptions. Mary McNamara, The Mercury News, 15 May 2024 New York City — Up against her biological clock, Traci Kodeck faced a tough decision at age 39. Nikki Battiste, CBS News, 9 May 2024 But a new study published on Friday in Cell Metabolism found that while pregnancy accelerates the body’s biological clock, much of that effect is reversed after delivery, especially in people who breastfeed. Annalisa Merelli, STAT, 22 Mar. 2024 Some scientists suggest that your biological clock gets out of sorts. Amy Huschka, Detroit Free Press, 9 Mar. 2024 Staying in education can slow down your biological clock and reduce the signs of aging, according to a new study. Nick Morrison, Forbes, 1 Mar. 2024 In the wide-ranging interview, Agron also discussed her role in the upcoming Hulu drama film Clock, centered on a woman who enrolls in a clinical trial to fix her broken biological clock amid pressure to have children, and looked back on her time on Glee. Jessica Wang,, 8 May 2023 Sunlight plays a vital role in regulating your circadian rhythm—the 24-hour biological clock that governs many body functions, including your sleep-wake cycle, temperature, and energy levels. Julia Ries, SELF, 3 Nov. 2023 Humans have a 24-hour biological clock that regulates a number of physiological processes including sleep patterns, eating and digesting, blood pressure, body temperature, and how hormones are regulated. Kaitlin Sullivan, Health, 25 Aug. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'biological clock.' 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

1941, in the meaning defined above

Time Traveler
The first known use of biological clock was in 1941

Dictionary Entries Near biological clock

Cite this Entry

“Biological clock.” Dictionary, Merriam-Webster, Accessed 14 Jun. 2024.

Kids Definition

biological clock

: a mechanism that exists in living things and controls the timing of behaviors and bodily functions which occur in cycles

Medical Definition

biological clock

: an inherent timing mechanism in a living system (as a cell) that is inferred to exist in order to explain various cyclical behaviors and physiological processes

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