ejector

noun

1. One who, or that which, ejects or dispossesses.
2. A jet jump for lifting water or withdrawing air from a space.
3. ejector seat: a pilot's seat in an airplane that can be forcibly ejected in the case of an emergency; then the pilot descends by parachute.
4. That part of the mechanism of a breech-loading firearm which ejects the empty shell.
5. A lever for removing circuit boards from an electronic chassis.