dogwatch

• dog watch, dog-watch

dog +‎ watch, perhaps a calque of German Hundewache.

• IPA^(key): /ˈdɒɡwɒt͡ʃ/

dogwatch (plural dogwatches)

1. (nautical) Aboard a ship, either of the two short two-hour watches that take place between 4 p.m. and 8 p.m.
   • 1888–1891, Herman Melville, “[Billy Budd, Foretopman.] Chapter XII.”, in Billy Budd and Other Stories, London: John Lehmann, published 1951, →OCLC:

     […] in the last dog-watch when the drawing near of twilight induced revery […]

2. (by extension) A night shift, or other very late or early period of duty.
   • 1946, Milton “Mezz” Mezzrow, Bernard Wolfe, “Not too Far Tangent”, in Really the Blues, New York, N.Y.: Random House, book 1 (1899–1923: A Nothin’ but a Child), page 22:

     The girls we knew were all on the dogwatch, from four to twelve in the morning.

3. (nautical) A very brief period of naval service.
   • 1972, George Carroll Dyer, The Amphibians Came to Conquer, page 265:

     At that time, Captain Thomas G. Peyton, U.S. Navy, who had only served a dog watch as Captain of the Port at Noumea, New Caledonia, reported for this important billet.

• watchdog