noun

• Any person or thing that brings stability.
• Any substance added to something in order to stabilize it, as for example a fuel additive that prolongs the shelf life of petrol.
• An additional wheel on a bicycle to keep it upright to assist a learner.
• A gyroscopically controlled fin or similar device that prevents the excess rolling of a ship in rough seas.
• An airfoil that stabilizes the flight of an aircraft or missile.
• (textiles) A piece of backing fabric used in embroidery.
• (mathematics) For a group operating on a set and an element x of the set, the set of all group elements fixing x.