Definitions for "Circadian rhythm"
a biological rhythm or cycle of behaviour which is repeated every 24 hours.
A biological rhythm that has a period length of about 24 hours.
An innate, daily, fluctuation of physiological and behavioral functions, including sleep waking, generally tied to the 24 hour day-night cycle but sometimes to a measurably different (e.g., 23 or 25 hour) periodicity when light/dark and other time cues are removed.
the synchronized action of the body's impulse to stay awake and fall asleep.
a rhythmic process within an organism occurring independently of external synchronizing signals.