You can retrieve this weapon after it is thrown as a 1-shot action.
This is not a maneuver in itself, and works along with other maneuvers (most particularly Throw).
In the case of an off-hand weapon, this indicates you attack your off-hand weapon to your main weapon. You can use return with either of them.
In most cases, Return means the weapon is attached to a string and drawn back to you. Such a stringed weapon has a maximum range of ten meters. In some cases, it actually flies back to you after being thrown.