ejector

One who, or that which, ejects or dispossesses.

(mechanics) A jet jump for lifting water or withdrawing air from a space.

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.

That part of the mechanism of a breech-loading firearm which ejects the empty shell.

A lever for removing circuit boards from an electronic chassis.