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
Kait Hanson, Southern Living, 2 Nov. 2024
It's known for capitalizing on Texas' extreme climate and its pronounced diurnal and seasonal temperature variations to craft intense and flavorful bourbons.
—Joseph V Micallef, Forbes, 29 Oct. 2024
Nighttime temperatures in the 50s and 60s helped to offset daytime conditions that often saw the mercury rising into the 90s and low 100s, but that diurnal swing alone wouldn’t be enough without human intervention.
—Jeremy Repanich, Robb Report, 18 Aug. 2024
As a diurnal ambush predator, this reptile was likely settling in for a night of rest before emerging in the daylight to hunt lizards, rodents and other prey.
—Liz Lindqwister, Smithsonian Magazine, 9 July 2024
See all Example Sentences for diurnal 
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Adjective
Vultures are large, daytime (diurnal) raptors that primarily feed on the decaying flesh of dead animals, known as carrion.
—Kait Hanson, Southern Living, 2 Nov. 2024
It's known for capitalizing on Texas' extreme climate and its pronounced diurnal and seasonal temperature variations to craft intense and flavorful bourbons.
—Joseph V Micallef, Forbes, 29 Oct. 2024
Nighttime temperatures in the 50s and 60s helped to offset daytime conditions that often saw the mercury rising into the 90s and low 100s, but that diurnal swing alone wouldn’t be enough without human intervention.
—Jeremy Repanich, Robb Report, 18 Aug. 2024
As a diurnal ambush predator, this reptile was likely settling in for a night of rest before emerging in the daylight to hunt lizards, rodents and other prey.
—Liz Lindqwister, Smithsonian Magazine, 9 July 2024
See all Example Sentences for diurnal
Dictionary Entries Near diurnal
Cite this Entry
“Diurnal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diurnal. Accessed 15 Nov. 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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