circadian

English

Etymology

From Latin circā (“about”) and diēs (“a day”) with the English suffix -an.

Adjective

circadian (comparative more circadian, superlative most circadian)

1. (biology) of, relating to, or showing rhythmic behaviour with a period of 24 hours; especially of a biological process
   • 2000, Arnold Sameroff, et al., Handbook of Developmental Psychopathology, page 310

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

   • 2002, Jill B. Becker, Behavioral Endocrinology, page 483

     To summarize, the circadian system, particularly the SCN, controls the circadian pattern of melatonin release in mammals.

   • 2005, Paul Martin, Counting Sheep: The Science and Pleasures of Sleep and Dreams, page 114

     The most obvious circadian rhythm is the daily cycle of sleep and activity.

Derived terms

• circadian rhythm

Translations

circadian

French: circadien (fr) Icelandic: dægur- (is), sólarhrings- (is)

Italian: circadiano (it)

See also

• infradian
• ultradian