trackball
/ˈtrækˌbɔl/
noun
- A pointing device for a computer that consists of a ball held in a socket, which the user rolls with their hand to move the cursor on screen.
- The arcade game used a large trackball instead of a joystick for control.
- My grandfather prefers using a trackball because it doesn't require moving his whole arm like a mouse.
- Some people find a trackball more comfortable for their wrist than a traditional mouse.