follow Dictionary.com

Word of the Day
Wednesday, May 15, 2013

Definitions for circadian

  1. noting or pertaining to rhythmic biological cycles recurring at approximately 24-hour intervals.

Learn something
new every day


GET OUR


Thank youfor signing up
Get the Word of the Day Email
Citations for circadian
My circadian clock, which puts me to sleep at night and wakes me up in the morning in a regular twenty-four-hour fashion, has a larger arc that seems set at twenty-four weeks. Jeanette Winterson, Written on the Body, 1993
Even a guard on night duty succumbs to the body's natural circadian rhythms and would be far from alert. Clive Cussler, The Jungle, 2010
Origin of circadian
1955-1960
Circadian was first used to apply to the "circadian rhythms" of the body, primarily our daily internal cycles of hunger, rest and wakefulness. It comes from the Latin roots circā meaning "about" and di meaning day.