Definition of spotters:
(n) :
A person who observes something.
(n) :
(weightlifting, gymnastics, climbing) One who supervises a person performing an activity, in order to help them should they be unable to complete it.
(n) :
(motor racing) A team member responsible for communication with the driver to keep them up-to-date about on-track events, such as other nearby cars.
(n) :
A member of a sniper team who in addition to this function is responsible for providing additional information about targets from a different point of view.
(n) :
(US) A person who gives directions for a crane or vehicle (that is challenging to navigate) from a different point of view to the moved load.
(n) :
(broadcasting) A person employed to assist a sports presenter by identifying the players or events during a game.