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

For these birds, the return of the sunlight signaled the start of a new day, effectively resetting their biological clocks, Aguilar said. —Ashley Strickland, CNN Money, 13 Oct. 2025

Williams notes that many successful women in their 30s and 40s also feel the biological clock ticking, which makes slowing down seem impossible. —Essence, 24 Sep. 2025

Surviving multiple extreme heat events over two years may accelerate a person’s biological clock by about eight to 11 days.2 Heat Waves May Speed Up ‘Biological Clock’ The 15-year study included 24,922 adults in Taiwan and recorded about 30 heat waves during that time. —Stephanie Brown, Verywell Health, 4 Sep. 2025

In addition to diet choices, a combination of supplements and exercise might also help pump the brakes on your biological clock. —Sarah Garone, Health, 27 Aug. 2025

Word History

First Known Use

1941, in the meaning defined above

Rhymes for biological clock

• aftershock
• antiknock
• arawak
• hollyhock
• interlock
• isopach
• manioc
• shuttlecock
• tomahawk
• weathercock
• alcock
• beanstalk

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