Rover

1. One who practices robbery on the seas; a pirate.
2. A sort of arrow.
3. One who wanders about by sea or land; a wanderer; a rambler.
4. 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.
5. Casual marks at uncertain distances.
6. Hence, a fickle, inconstant person.