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Definitions

circadian rhythm

NOUN
biological clock
Synonyms
WEAK
biological rhythm biorhythm body clock circadian clock cycles
NOUN
biological rhythm
Synonyms
WEAK
biorhythm body clock cycles internal clock
NOUN
body clock
Synonyms
WEAK
biological rhythm biorhythm circadian clock internal clock

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

She argues that switching to daylight-saving time ultimately plays havoc with our circadian rhythm — that is, our internal biological clock.

From MarketWatch • Mar. 6, 2026

I’ve learned from experts over and over about how exposing yourself to natural light, even on an overcast day, either resets or talks to your circadian rhythm.

From The Wall Street Journal • Feb. 16, 2026

These devices tracked periods of rest and activity, allowing researchers to analyze circadian rhythm patterns.

From Science Daily • Jan. 3, 2026

"These things are not rocket science, but they're really fundamental to having a good, healthy circadian rhythm and a good healthy physiology through the winter."

From BBC • Nov. 10, 2025

Not only was this arrangement bad for the astronaut’s circadian rhythm, but the astronaut who was on duty made enough noise as he went about his work to keep his partner awake.

From "Flying to the Moon: An Astronaut's Story" by Michael Collins