n. [ F. nocturne, fr. L. nocturnus. See Nocturnal, and cf. Nocturne. ]
a. [ L. nocturnalis, nocturnus, fr. nox, noctis, night. See Night, and cf. Nocturn. ]
n. An instrument formerly used for taking the altitude of the stars, etc., at sea. I. Watts. [ 1913 Webster ]
adv. By night; nightly. [ 1913 Webster ]
n. [ F. See Nocturn. ] (Mus.) A night piece, or serenade. The name is now used for a certain graceful and expressive form of instrumental composition, as the nocturne for orchestra in Mendelsohn's “Midsummer-Night's Dream” music. [ 1913 Webster ]