A vagabond, a tramp, an unsteady, restless person, one who by habit doesn't settle down or marry.
A vehicle for exploring extraterrestrial bodies.
(Australian Rules football) A position that is one of three of a team's followers, who follow the ball around the ground. Formerly a position for short players, rovers in professional leagues are frequently over 183 cm (6').
(croquet) A ball which has passed through all the hoops and would go out if it hit the stake but is continued in play; also, the player of such a ball.