the after part of the upper deck of a ship. In former times the upper deck of a line-of-battle ship or frigate ended at the mainmast, and was connected with the forecastle by two narrow passages, or gangways running along the sides. The quarterdeck is the residence and symbol of authority in a warship. The starboard, or right side looking forward, is reserved to the senior officer. A sailor who had a complaint to make was said to come to the mainmast, because he placed himself at the forward end of the quarterdeck near the mast. According to the ancient custom of the sea, the quarterdeck is to be saluted by all who come upon it, and the salute is returned by all officers present.