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 of nocturnal

• night
• midnight

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

Many birds migrate at night using dark-sky cues, and nocturnal mammals rely on natural moonlight and starlight to survive. —Hanna Wickes, Kansas City Star, 12 May 2026

Against the backdrop of a rainy, nocturnal London, O’Shaughnessy reprises his role as photographer Miles who obsessively captures unforgiving, morbid portraits of unaware strangers. —Melanie Goodfellow, Deadline, 11 May 2026

The sensory cues involved are probably extremely subtle, and the animal itself is nocturnal, elusive and endangered. —Scott Travers, Forbes.com, 10 May 2026

That said, Elkmont isn’t the only spot for nocturnal magic. —Stephanie Vermillion, Travel + Leisure, 9 May 2026

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

Rhymes for nocturnal

• diurnal
• eternal
• external
• fraternal
• infernal
• internal
• maternal
• paternal
• pimpernel
• colonel
• journal
• kernel

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