noc·tur·nal /nɑkˈtɝnḷ/ 形容詞
1. Of, pertaining to, done or occuring in, the night; as, nocturnal darkness, cries, expedition, etc.; -- opposed to diurnal.
2. Having a habit of seeking food or moving about at night; as, nocturnal birds and insects; raccoons are nocturnal.; -- of animals.
Noc·tur·nal, n. An instrument formerly used for taking the altitude of the stars, etc., at sea.
adj 1: 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" [ant: diurnal]
2: of or relating to or occurring in the night; "nocturnal
3: of or during or relating to the night; "a nocturnal
journey"; "nocturnal stillness"; "nocturnal predators"