diurnal
Americanadjective
noun
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Liturgy. a service book containing offices for the daily hours of prayer.
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Archaic. a diary.
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Archaic. a newspaper, especially a daily one.
adjective
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happening during the day or daily
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(of flowers) open during the day and closed at night
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(of animals) active during the day Compare nocturnal
noun
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Occurring once in a 24-hour period; daily.
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Having a 24-hour cycle. The movement of stars and other celestial objects across the sky are diurnal.
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Most active during the daytime. Many animals, including the apes, are diurnal.
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Having leaves or flowers that open in daylight and close at night. The morning glory and crocus are diurnal.
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Compare nocturnal
Other Word Forms
Etymology
Origin of diurnal
1400–50; late Middle English < Latin diurnālis, equivalent to diurn ( us ) daily + -ālis -al 1
Explanation
If it’s 9:00 at night and your mom wants you to do the dishes, you could try to put it off until the next day by politely pointing out that you are a diurnal animal. That means you get most of your activities done during the day. The adjective diurnal can be used to describe anything that takes place in the daytime, but it is most often used in the field of biology to describe animals that are active during the day and then sleep at night. Animals with the opposite schedule are said to be nocturnal, which means they’re active at night and sleep in the daytime. Diurnal can also be used to describe something that has a daily cycle, such as a diurnal tide that occurs once each day.
Vocabulary lists containing diurnal
Don't Distress: Words With Irregular Opposites
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The Hitchhiker's Guide to the Galaxy
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Life of Pi
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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.
Diurnal preference also manifests as differences in normal sleep.
From Scientific American • Feb. 11, 2014
The Queen Dowager died, however, within a few months; the "Diurnal of Occurrents" says on the 24th of November.
From The Works of John Knox, Vol. 1 (of 6) by Laing, David
Cleiveland, in his Character of a London Diurnal, says, "the original sinner of this kind was Dutch; Gallo-belgicus the Protoplast, and the Modern Mercuries but Hans en kelders."
From Lives of the Poets, Volume 1 by Johnson, Samuel
Having thus endeavoured to give an account of the Diurnal and Menstrual Periods of Tides; It remains that I endeavour the like as to the Annual.
From Philosophical Transactions of the Royal Society - Vol 1 - 1666 Giving some Accompt of the present Undertakings, Studies, and Labours of the Ingenious in many considerable parts of the World by Oldenburg, Henry
Mr. Edward Doubleday, in his “Genera of Diurnal Lepidoptera,” says, “The Papilionidæ may be known by the apparently four-branched median nervule and the spur on the anterior tibiæ, characters found in no other family.”
From Contributions to the Theory of Natural Selection A Series of Essays by Wallace, Alfred Russel
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.