rover

Concise Oxford English Dictionary © 2008 Oxford University Press:
rover1

▶noun

• 1 a person who spends their time wandering.

• 2 (in various sports) a player not restricted to a particular position on the field.

  ■ Australian Rules one of the three players making up a ruck.

• 3 a vehicle for driving over rough terrain.

• 4 Archery a mark for long-distance shooting.

  ■ a mark chosen at random and not at a determined range.

Concise Oxford English Dictionary © 2008 Oxford University Press:
rover2

▶noun archaic a pirate.

– origin ME: from Mid. Low Ger., MDu. rōver, from rōven ‘rob’; rel. to reave.