Approximately, about, around (typically in relation to time)

A surname.

plural of circadian rhythm

(biology) Occurring or having cycles of approximately annual periodicity

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

The "internal body clock" that regulates the (roughly) 24-hour cycle of biological processes in animals and plants.

Disruption to the body's biological clock caused by a sudden shift in daily rhythm.

The region of the sublittoral zone which extends from the lower limit of the infralittoral to the maximum depth at which photosynthesis is still possible.

Situated in this region of the sublittoral zone.

(biology) of, relating to, or showing rhythmic behaviour with a period of a lunar month