- nocturnal - belonging to or active during the night; "nocturnal animals are active at night"; "nocturnal plants have flowers that open at night and close by day"
Antonym: diurnal
- nocturnal - of or relating to or occurring in the night; "nocturnal darkness"
- nocturnal - of or during or relating to the night; "a nocturnal journey"; "nocturnal stillness"; "nocturnal predators"
Antonym: daytime (indirect, via nighttime)
- nocturnal - of or during or relating to the night; "a nocturnal journey"; "nocturnal stillness"; "nocturnal predators"