nocturnal

adjective

noc·​tur·​nal näk-ˈtər-nᵊl How to pronounce nocturnal (audio)
1
: of, relating to, or occurring in the night
a nocturnal journey
nocturnal activities
2
: active at night
a nocturnal predator
nocturnal insects, such as mosquitoes
nocturnally adverb

Examples of nocturnal in a Sentence

he bought a new telescope so he could pursue his favorite nocturnal hobby of astronomy
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Arcturus is the brightest star in the constellation Bootes the Herdsman, although the constellation really looks more like a giant nocturnal kite with Arcturus marking the tail. Mike Lynch, Twin Cities, 1 June 2025 There will be guided night hikes with night vision goggles to see owls, bats and other nocturnal creatures, as well as visiting ambassador animals, demonstrations, crafts and more. Anna Ortiz, Chicago Tribune, 31 May 2025 As with everything Banksy, siting and context are chief among the avenues of investigation into the man’s intent and into his his hilariously ruthless nocturnal execution of his art. Guy Martin, Forbes.com, 30 May 2025 In early 2007, Albany residents called local authorities with reports of typically nocturnal bats flying in broad daylight. Lillian Ali, Smithsonian Magazine, 30 May 2025 See All Example Sentences for nocturnal

Word History

Etymology

Middle English, borrowed from Anglo-French & Late Latin; Anglo-French nocturnel, borrowed from Late Latin nocturnālis "for night use," from Latin nocturnus "of or occurring at night" (from noct-, nox night entry 1 + -urnus, temporal suffix, as in diurnus "of the day") + -ālis -al entry 1 — more at journal

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of nocturnal was in the 15th century

Browse Nearby Words

Cite this Entry

“Nocturnal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nocturnal. Accessed 11 Jun. 2025.

Kids Definition

nocturnal

adjective
noc·​tur·​nal näk-ˈtərn-ᵊl How to pronounce nocturnal (audio)
1
: of, relating to, or occurring in the night
a nocturnal journey
2
: active at night
nocturnal insects
nocturnally adverb
Etymology

from early French nocturnal, nocturnel or Latin nocturnalis, both meaning "nocturnal," derived from earlier Latin noct-, nox "night" — related to equinox

Medical Definition

nocturnal

adjective
noc·​tur·​nal näk-ˈtərn-ᵊl How to pronounce nocturnal (audio)
1
: of, relating to, or occurring at night
nocturnal myoclonus
2
: characterized by nocturnal activity
a nocturnal form of filariasis

More from Merriam-Webster on nocturnal

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