from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Nautical Either of two short periods of watch duty, from 4 to 6 P.M. or 6 to 8 P.M.
- n. A late night shift.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Aboard a ship, either of the two short two-hour watches that take place between 4 p.m. and 8 p.m.
- n. A night shift, or other very late or early period of duty.
from the GNU version of the Collaborative International Dictionary of English
- n. A half watch; a watch of two hours, of which there are two, the first dogwatch from 4 to 6 o'clock, p. m., and the second dogwatch from 6 to 8 o'clock, p. m.
from The Century Dictionary and Cyclopedia
- n. Nautical, a watch of two hours, arranged so as to alter the watches kept from day to day by each division of the crew. The first dog-watch is from 4 to 6 p. m., the second from 6 to 8 p. m. See watch.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. either of two short watches: from 4-6 pm or 6-8 pm
Probably from dog-sleep, a light or interrupted sleep.(American Heritage® Dictionary of the English Language, Fourth Edition)
From dog + watch. (Wiktionary)