Nocturnal

from WordNet (r) 3.0 (2006)

nocturnal
    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
       darkness"

from The Collaborative International Dictionary of English v.0.48

Nocturnal \Noc*tur"nal\, a. [L. nocturnalis, nocturnus, fr. nox,
   noctis, night. See {Night}, and cf. {Nocturn}.]
   1. Of, pertaining to, done or occuring in, the night; as,
      nocturnal darkness, cries, expedition, etc.; -- opposed to
      {diurnal}. --Dryden.
      [1913 Webster]

   2. Having a habit of seeking food or moving about at night;
      as, nocturnal birds and insects; raccoons are nocturnal.;
      -- of animals.
      [1913 Webster +PJC]

from The Collaborative International Dictionary of English v.0.48

Nocturnal \Noc*tur"nal\, n.
   An instrument formerly used for taking the altitude of the
   stars, etc., at sea. --I. Watts.
   [1913 Webster]

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