night-owl

Noun

night owl (plural night owls)

1. (literally) An owl (order Strigiformes) that is nocturnal.
   • Their Weapons like to Lightning, came and went: / Our Souldiers like the Night-Owles lazie flight, / Or like a lazie Threſher with a Flaile, / Fell gently downe, as if they ſtrucke their Friends.c. 1591–1592 (date written), William Shakespeare, “The Third Part of Henry the Sixt, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard...
2. (idiomatic) One who goes to bed late, or stays up late at night or in the early hours of the morning.
   • "You are one night owl, Monsieur Reetchie," he said. / "And you seem to prefer the small hours for your visits, Monsieur de St. Gré," I could not refrain from replying.1904 May, Winston Churchill, “Louisville Celebrates”, in The Crossing, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd., →OCLC, book III (Louisiana), page 461

   Synonyms:

   nighthawk, night person

   Antonyms:

   day lark, early bird, lark, morning person

3. A musical instrument which imitates an owl's hoot, consisting of a receptacle partly filled with water and a mouthpiece that is blown into.
   • The night-owl,—a mug-shaped instrument, with an orifice in its side, through which a whistle is inserted,—when used, is partly filled with water, to give the tremulous owl-hoot sound.1874 May, James Judson Lord, “Haydn’s Children’s Symphony [actually the Toy Symphony, possibly by Leopold Mozart or Edmund Angerer]”, in [Mary Mapes Dodge], editor, St. Nicholas, volume I, number 7...