diurnal
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.
Origin of diurnal
1Other words from diurnal
- 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
Words that may be confused with diurnal
- diurnal , nocturnal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
British Dictionary definitions for diurnal
/ (daɪˈɜːnəl) /
happening during the day or daily
(of flowers) open during the day and closed at night
(of animals) active during the day: Compare nocturnal
a service book containing all the canonical hours except matins
Origin of diurnal
1Derived forms of diurnal
- 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
[ dī-ûr′nəl ]
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.
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