nocturnal

adjective

noc·​tur·​nal näk-ˈtər-nᵊl How to pronounce nocturnal (audio)
Synonyms of nocturnal
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
näk-ˈtər-nᵊl-ē How to pronounce nocturnal (audio)
adverb

Synonyms of nocturnal

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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.
But a myth about these shy, semi-nocturnal predators may have been behind the species’ extinction. — Ashley Strickland, CNN Money, 2 Sep. 2026 The nocturnal parrots with their owl-like faces remain critically endangered, conservationists say. — Adela Suliman, NBC news, 1 Sep. 2026 Created by Weisman, the original Walt Disney Television Animation series, which aired from 1994-1997, revolved around nocturnal creatures known as gargoyles that turn to stone during the day. — Denise Petski, Deadline, 31 Aug. 2026 Thanks to all these survey techniques, Arizona scientists are making inroads in illuminating the secret lives of these nocturnal critters. — Shi En Kim, AZCentral.com, 28 Aug. 2026 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

Rhymes for nocturnal

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Browse Nearby Words

nocturn
nocturnal
nocturnality
See all Nearby Words

Cite this Entry

“Nocturnal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nocturnal. Accessed 7 Sep. 2026.

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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
-ᵊl-ē How to pronounce nocturnal (audio)
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
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