di·ur·nal
dī-ˈər-nᵊl 
1
a
biology
: active chiefly in the daytime
diurnal animals
b
: of, relating to, or occurring in the daytime
the city's diurnal noises
c
botany
: opening during the day and closing at night
diurnal flowers
2
a
: recurring every day
diurnal tasks
b
: having a daily cycle
diurnal tides
1
Synonyms
Examples of diurnal in a Sentence
Adjective
a love as constant and certain as the diurnal tides
Noun
a collection of diurnals containing essays by preeminent 19th-century American writers and thinkers
Recent Examples on the Web
Finian Curran/queens University News Service, Charlotte Observer, 9 May 2024
Because the specimens were all collected during the daytime, they are believed to be diurnal.
—Brendan Rascius, Miami Herald, 19 Apr. 2024
The ascendant or the rising sign is more about the diurnal rotation of the earth.
—Cnt Editors, Condé Nast Traveler, 11 Apr. 2024
Frogs and crickets, common elements of an evening soundscape, started to call, while diurnal cicadas stopped making noise.
—Carlyn Kranking, Smithsonian Magazine, 5 Apr. 2024
See all Example Sentences for diurnal 
Adjective
Songbirds are mostly diurnal, so their images were captured during the day, with a few extending into early evening.
—Finian Curran/queens University News Service, Charlotte Observer, 9 May 2024
Because the specimens were all collected during the daytime, they are believed to be diurnal.
—Brendan Rascius, Miami Herald, 19 Apr. 2024
The ascendant or the rising sign is more about the diurnal rotation of the earth.
—Cnt Editors, Condé Nast Traveler, 11 Apr. 2024
Frogs and crickets, common elements of an evening soundscape, started to call, while diurnal cicadas stopped making noise.
—Carlyn Kranking, Smithsonian Magazine, 5 Apr. 2024
See all Example Sentences for diurnal
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'diurnal.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Dictionary Entries Near diurnal
Cite this Entry
“Diurnal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diurnal. Accessed 2 Jul. 2024.
Copy CitationMedical Definition
diurnal
adjective
di·ur·nal
dī-ˈərn-ᵊl
1
: having a daily cycle
diurnal rhythms
2
a
: of, relating to, or occurring in the daytime
diurnal activity
b
: chiefly active during the daytime
diurnal mosquitoes
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