follow Dictionary.com

Dictionary.com's Word of the Year is...

circadian

[sur-key-dee-uh n, -kad-ee-, sur-kuh-dee-uh n] /sɜrˈkeɪ di ən, -ˈkæd i-, ˌsɜr kəˈdi ən/
adjective
1.
noting or pertaining to rhythmic biological cycles recurring at approximately 24-hour intervals.
Origin
1955-1960
1955-60; < Latin circā about + di(ēs) day + -an
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for circadian
  • Other brands contain melatonin, the hormone that maintains your body's circadian clock, but also can make you sleepy.
  • The profile of this pressure is believed to follow characteristic circadian patterns.
  • Sleep researchers have found that you can reset your circadian clock fairly easily.
  • One of the brain centers that is thus permanently damaged is the circadian clock.
  • Once there, it can produce sleepiness either directly or by acting on the circadian clock.
  • circadian rhythms are almost impossible to move away from mentally.
  • The hormone melatonin regulates the circadian rhythm--the sleep cycle.
  • Reference to length of circadian rhythm also adjusted.
  • The same is true for circadian rhythms in fruit flies.
  • On a moon, eclipses would be part of a second circadian rhythm of sorts.
British Dictionary definitions for circadian

circadian

/sɜːˈkeɪdɪən/
adjective
1.
of or relating to biological processes that occur regularly at about 24-hour intervals, even in the absence of periodicity in the environment See also biological clock
Word Origin
C20: from Latin circa about + diēs day
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for circadian
adj.

coined 1959 from Latin circa "about" (see circa) + diem, accusative singular of dies "day" (see diurnal). The original use is in circadian rhythm.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
circadian in Medicine

circadian cir·ca·di·an (sər-kā'dē-ən, -kād'ē-, sûr'kə-dī'ən, -dē'-)
adj.
Relating to biological variations or rhythms with a cycle of about 24 hours.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Difficulty index for circadian

Some English speakers likely know this word

Word Value for circadian

0
17
Scrabble Words With Friends