A square or oblong cabin erected on the deck of a ship. In the sailing warships of the Royal Navy it was known, in a perverse sort of way, as the round house because one could walk round it. Originally, in the 17th and 18th centuries, it was the name given to the upper coach. However, by the end of the 18th century the term round house was used to describe the lavatory fitted in a warship's sickbay for men who were unable, because of illness or wounds, to get forward to the heads.
In many merchant vessels, particularly sailing ships in the days of the clipper ships and, later, the big trading barques, a large deckhouse was erected just abaft the foremast to house the galley and to provide quarters for the crew on watch.
Subjects: Maritime History — Warfare and Defence.