ejector

/ɪˈdʒɛktər/
noun
  1. A device or mechanism that forces something out, such as a part in a machine or a seat in an aircraft.
    • The fighter jet's ejector seat saved the pilot's life during the emergency.
    • The printer's ejector pushes the paper out after printing is complete.
    • The engineer replaced the broken ejector in the assembly line robot.
Antonyms