What does nocturnal mean?
Nocturnal is an adjective describing something that happens, lives, or is active at night. It is especially associated with animals and plants whose main period of activity occurs after dark, such as owls, bats, moths, and certain flowering plants, but it can also describe people and human activities. The word often conveys a sense of darkness, secrecy, or an unusual relationship with the night, although its basic meaning is simply connected with nighttime. In general use, a nocturnal event is one that takes place late at night, while in biological contexts the term identifies organisms adapted to nighttime conditions. It contrasts with diurnal, which refers to daytime activity, and is related to nightly, though nightly more strongly suggests something happens every night. The related adverb nocturnally is used in formal and scientific writing.
Occurring, happening, or being active during the night.
"The nocturnal animals hide during the day."
The adjective is formal and is especially common in biological and ecological writing.
A person who is active or awake at night.
"The nocturnal moved quietly through the empty city."
The noun is relatively uncommon and has a literary or informal flavor.
The plural is possible when the noun is used for people who are active or awake at night.
"The nocturnals gathered in the abandoned station."
Many familiar animals, including owls and many moths, are nocturnal: their daily lives unfold after the sun goes down.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of nocturnal
Nocturnal comes from Latin nocturnalis, meaning “of or belonging to the night.” The Latin adjective was formed from nox, “night,” a root that also appears in English words such as nocturne and nightly. English borrowed the word in the 16th century, initially in contexts connected with nighttime, darkness, and things occurring after dark.
Related word forms
How nocturnal is actually used
Nocturnal is formal and descriptive. It is especially common in biology and descriptions of animals, but it can also refer to people, activities, or events that take place at night. The related adverb is nocturnally.
Easily confused with nocturnal
Nocturnal describes activity during the night, whereas diurnal describes activity during the day.
Nightly can mean happening every night, while nocturnal more directly means occurring or active at night.