Search Result for "trackball": 
Wordnet 3.0

NOUN (1)

1. an electronic device consisting of a rotatable ball in a housing; used to position the cursor and move images on a computer screen;
- Example: "a trackball is essentially an upside-down mouse"



WordNet (r) 3.0 (2006):

trackball
    n 1: an electronic device consisting of a rotatable ball in a
         housing; used to position the cursor and move images on a
         computer screen; "a trackball is essentially an upside-down
         mouse"