- noun a pointing device that is operated by moving it across a flat surface. As the mouse is moved, a ball inside spins and turns two sensors that feed the horizontal and vertical movement back to the computer.
- A computer mouse in which the mechanical movements of an incorporated ball are converted into cursor or pointer movements on the screen. Such a mouse has a ball underneath that can roll in any direction along two planes, and its movements are converted by sensors into the appropriate signals. An optical mouse utilizes light to track mouse movements over a special grid.