Boat'swain, n.

(colloquially, bō'sn), n. [A-S. bātswān; bāt, boat, and swān, swain, servant.] (Naut.) An officer who has charge of the boats, sails, rigging, colors, anchors, cables, cordage, &c., of a ship, and who also summons the crew, and performs various other duties. Totten.

Boatswain's mate, a petty officer who is assistant to the boatswain in all his duties. Totten.