circadian

adj

(biology) of, relating to, or showing rhythmic behaviour with a period of 24 hours; especially of a biological process

The circadian rhythm regulates the sleep-wake cycle.

意味（1）

(biology) of, relating to, or showing rhythmic behaviour with a period of 24 hours; especially of a biological process

The circadian clock is involved in the regulation of the diurnal sleep-wake cycle, […].