of or relating to a day or each day; daily.
of or belonging to the daytime (opposed to nocturnal).
Botany. showing a periodic alteration of condition with day and night, as certain flowers that open by day and close by night.
active by day, as certain birds and insects (opposed to nocturnal).
Liturgy. a service book containing offices for the daily hours of prayer.
Archaic. a diary.
Archaic. a newspaper, especially a daily one.
- di·ur·nal·ly, adverb
- di·ur·nal·ness, noun
- trans·di·ur·nal, adjective
- un·di·ur·nal, adjective
- un·di·ur·nal·ly, adverb
- diurnal , nocturnal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use diurnal in a sentence
I think we should diurnally station a good London band on high, and play his Majesty to bed—the sun.Evan Harrington, Complete | George Meredith
Mountain and valley breezes furnish another example of diurnally reversed winds.Meteorology | Charles Fitzhugh Talman
Why or how does seven-and-sixpence diurnally represent one the equal of the best in any society of the land?Cornelius O'Dowd Upon Men And Women And Other Things In General | Charles Lever
It had never before dawned upon us that we thus added three uncounted miles to our fourteen diurnally counted ones.Lippincott's Magazine, December, 1885 | Various
British Dictionary definitions for diurnal
happening during the day or daily
(of flowers) open during the day and closed at night
a service book containing all the canonical hours except matins
- diurnally, adverb
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
Scientific definitions for diurnal
Occurring once in a 24-hour period; daily.
Having a 24-hour cycle. The movement of stars and other celestial objects across the sky are diurnal.
Most active during the daytime. Many animals, including the apes, are diurnal.
Having leaves or flowers that open in daylight and close at night. The morning glory and crocus are diurnal. Compare nocturnal.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.