'Nocturnal' definitions:
Definition of 'nocturnal'
From: WordNet
adjective
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]
adjective
Of or relating to or occurring in the night; "nocturnal darkness"
Definition of 'Nocturnal'
From: GCIDE
- Nocturnal \Noc*tur"nal\, n. An instrument formerly used for taking the altitude of the stars, etc., at sea. --I. Watts. [1913 Webster]