nocturnal

adjective

noc·​tur·​nal näk-ˈtər-nᵊl 

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 

adverb

Synonyms

• night
• nightly
• nighttime

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

Instead, Mixtape Pluto is subterranean and nocturnal, hedonistic one minute and aching with regrets the next, debauched but wounded. —Christopher R. Weingarten, Rolling Stone, 23 Sep. 2024

Per his own obituary, Rebecca’s son died of complications from a nocturnal seizure on June 18, 2010. —Nicole Briese, Peoplemag, 21 Sep. 2024

Witchy Owl Download This nocturnal friend might be up to some spooky trouble! —De Elizabeth, Parents, 20 Sep. 2024

Yashica For those wanting to keep their nocturnal discoveries after the night rambles are over, the device is capable of capturing 48-megapixel still images via a Galaxycore 1/2.9-inch CMOS sensor and a coated F1.0 aperture lens. —Paul Ridden, New Atlas, 18 Sep. 2024

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

Kids Definition

nocturnal

adjective

noc·​tur·​nal näk-ˈtərn-ᵊl 

1

: of, relating to, or occurring in the night

a nocturnal journey

2

: active at night

nocturnal insects

nocturnally

-ᵊl-ē 

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 

1

: of, relating to, or occurring at night

nocturnal myoclonus

2

: characterized by nocturnal activity

a nocturnal form of filariasis