- Also called able-bodied seaman. an experienced deck-department seaman qualified to perform routine sea duties.
- (in the British Navy and on British and U.S. merchant ships) a rating between ordinary seaman and leading seaman or boatswain’s mate. Abbreviation: A.B., AB
- an ordinary seaman, esp one in the merchant navy, who has been trained in certain skillsAlso: able seaman Abbreviation: AB, a.b.