Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.
circadian rhythm:see rhythm, biologicalrhythm, biological,
cyclic pattern of physiological changes or changes in activity in living organisms, most often synchronized with daily, monthly, or annual cyclical changes in the environment.
..... Click the link for more information. .
circadian rhythm[sər′kād·ē·ən ′rith·əm]
A self-sustained cycle of physiological changes that occurs over an approximately 24-hour cycle, generally synchronized to light-dark cycles in an organism's environment.