biological clock

noun

: 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

While the female biological clock is undoubtedly a factor in these results, women clearly feel a certain pressure to hit these particular milestones by this age. —Justin Gest, Newsweek, 11 Feb. 2025

If your job allows it, setting firm boundaries around work hours can prevent late-night tasks from disrupting your biological clock, which can lead to a reliance on catch-up sleep, Smith said. —Julianna Bragg, CNN, 15 Jan. 2025

Permanent Standard Time aligns more closely with human biological clocks, potentially improving sleep quality and overall health, as per the Oxford Academic. —David Faris, Newsweek, 29 Dec. 2024

Free-running time refers to the period in which an organism's biological clock, also known as its circadian rhythm, resets. —Michael Franco, New Atlas, 24 Dec. 2024

Word History

First Known Use

1941, in the meaning defined above

Kids Definition

biological clock

noun

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

Medical Definition

biological clock

noun

: 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