n. [ Boat + swain. ] 1. (Naut.) An officer who has charge of the boats, sails, rigging, colors, anchors, cables, cordage, etc., of a ship, and who also summons the crew, and performs other duties. [ 1913 Webster ]
2. (Zool.) (a) The jager gull. (b) The tropic bird. [ 1913 Webster ]
Boatswain's mate, an assistant of the boatswain. Totten. [ 1913 Webster ]