midwatch n a watch during the night (as from midnight to 8 a.m.) Usage(s) The signal for peace on the East Coast came one morning last week during a midwatch hour in a New York hotel. On the midwatch I had rigged a 200-watt cargo lamp, equipped with a reflector, at the side to direct boats to the quarter-deck sea-ladder. Synonym(s) graveyard watch middle watch night watch