1. n. the vertical lever used to control smaller aircraft. She pulled back on the joystick and the plane took off.
2. n. an electronic control device for computer games and other program control. (From sense 1) The ship’s first officer used a tiny joystick to control the computer program that guided the ship the next port.
3. n. the erect penis. (Usually objectionable.) He couldn’t seem to stop playing pocket pool with his joystick.