- (of a person, creature, group, or species) Primarily active during the night.
- nocturnal birds
- (of an occurrence) Taking place at night, nightly.
- a suspicious nocturnal outing
- French: nocturne
- German: nachtaktiv
- Portuguese: nocturno, noturno
- Russian: ночно́й
- Spanish: nocturno, noctámbulo, trasnochador
nocturnal (plural nocturnals)
- A person or creature that is active at night.
- (historical) A device for telling the time at night, rather like a sundial but read according to the stars.
- Synonyms: star clock
- 2015, David Wootton, The Invention of Science, Penguin 2016, p. 188:
- A rather different instrument was the nocturnal: it enabled you to tell the time at night, provided you knew the date, from the position of the stars in the constellation of the Great Bear, which rotate around the Pole Star.