nocturnal
adj.adj. describing animals that are active at night or things that happen during the night. You use this to talk about creatures that sleep while you are awake.
adj. relating to or occurring in the night; active primarily during the hours of darkness. Often used in biological contexts to describe animal behaviour or in literary contexts for night-time events.
Owls are nocturnal birds that hunt at night.
The zoo's nocturnal house allows visitors to observe animals that would normally be asleep during the day.
The city took on a different character after midnight, filled with the nocturnal sounds of distant sirens and the low hum of late-night delivery trucks.
From Middle French nocturnal, from Latin nocturnus (“nocturnal, nightly”), from Latin nox (“night”), from Proto-Indo-European nókʷts (“night”). Cognates include Ancient Greek νύξ (núx), Sanskrit नक्ति (nákti), Old English niht (English night) and Proto-Slavic noťь.
Typically used attributively before a noun; frequently contrasted with 'diurnal'.