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
See all Synonyms & Antonyms 
Example Sentences
he bought a new telescope so he could pursue his favorite nocturnal hobby of astronomy
Recent Examples on the Web The black ghost knifefish is, as its name implies, a nocturnal hunter. 
Elizabeth Kolbert, The New Yorker, 6 June 2022 The ghost bat is a nocturnal hunter that uses a combination of keen eyesight and echolocation to hunt and catch prey, wrapping its winglike arms around it, and in the case of budgies (a type of small parrot), eating it head-first. Kyle Mizokami, Popular Mechanics, 24 Mar. 2022 The nocturnal hunter appears to be targeting the city's plentiful downtown rat population. CBS News, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, USA TODAY, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, The Christian Science Monitor, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, ajc, 10 Jan. 2022 Neither plan on getting much sleep during the competition, as pythons are nocturnal, meaning the best time for hunting is late at night. Mary Pflum, NBC News, 4 Aug. 2022 There are some species of fish, like catfish and knife fish, that are nocturnal, Aqueon says. Clare Mulroy, USA TODAY, 8 July 2022 See More
Elizabeth Kolbert, The New Yorker, 6 June 2022 The ghost bat is a nocturnal hunter that uses a combination of keen eyesight and echolocation to hunt and catch prey, wrapping its winglike arms around it, and in the case of budgies (a type of small parrot), eating it head-first. Kyle Mizokami, Popular Mechanics, 24 Mar. 2022 The nocturnal hunter appears to be targeting the city's plentiful downtown rat population. CBS News, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, USA TODAY, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, The Christian Science Monitor, 11 Jan. 2022 The nocturnal hunter appears to be targeting the city’s plentiful downtown rat population. Christina Larson, ajc, 10 Jan. 2022 Neither plan on getting much sleep during the competition, as pythons are nocturnal, meaning the best time for hunting is late at night. Mary Pflum, NBC News, 4 Aug. 2022 There are some species of fish, like catfish and knife fish, that are nocturnal, Aqueon says. Clare Mulroy, USA TODAY, 8 July 2022 See More 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-ˈtər-nᵊl
1
: happening at night
a nocturnal journey
2
: active at night
nocturnal insects
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
nocturnal
adjective
as in night
of, relating to, or occurring in the night he bought a new telescope so he could pursue his favorite nocturnal hobby of astronomy Synonyms & Similar Words
Relevance
- night
- nighttime
- midnight
- nightly
- late
- overnight
Antonyms & Near Antonyms
- daily
- diurnal
- noon