nipple mouse definition, from Internet Connection, Inc.

Var. clit mouse, clitoris Common term for the pointing device used on IBM ThinkPads and a few other laptop computers. The device, which sits between the ‘g’ and ‘h’ keys on the keyboard, indeed resembles a rubber nipple intended to be tweaked by a forefinger. Many hackers consider these superior to the glide pads found on most laptops, which are harder to control precisely.