call button

Noun



 * 1) A button used to request assistance.
 * 2) A button used to request some form of mechanical service.
 * 3) A button used to request a walk signal at a pedestrian crossing.
 * 4) A button used to summon an elevator.
 * 1) A button used to request a walk signal at a pedestrian crossing.
 * 2) A button used to summon an elevator.
 * 1) A button used to summon an elevator.