- an inherent periodicity in the physiological processes of living organisms that is not dependent on the periodicity of external factors
- the hypothetical mechanism responsible for this periodicity
See also circadian
WordReference Random House Learner's Dictionary of American English © 2026
bi•oˈlog•i•cal ˈclock, n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2026- Physiologyan inborn mechanism of the body that controls its cycles, such as those of sleeping and waking.
- such a mechanism when it is seen as marking the passing of one's youth and esp. of a woman's ability to bear children:wanted to have a baby because she heard her biological clock ticking.
biolog′ical clock′, [Physiol.]
- Physiologyan innate mechanism of the body that regulates its rhythmic and periodic cycles, as that of sleeping and waking.
- 1950–55
Collins Concise English Dictionary © HarperCollins Publishers::
biological clock n
See also circadian
See also circadian
'biological clock' also found in these entries (note: many are not synonyms or translations):