1. One that makes or keeps something stable: "The New Deal equipped the economy with built-in stabilizers" (Arthur M. Schlesinger, Jr.)

2. A device, such as a gyroscopically controlled fin, that prevents excessive rolling of a ship in heavy seas.

3. An airfoil that stabilizes an aircraft or missile in flight.

4. Chemistry A substance that renders or maintains a solution, mixture, suspension, or state resistant to chemical change.