Source : Free On-Line Dictionary of Computing

double-click
     
         To click a {mouse} button twice in rapid
        succession without moving the mouse.  Often used as a
        shortcut, combining the actions of selecting, and then opening
        a document (or activating some other kind of object) within a
        {graphical user interface}.  Some {text editors} use
        double-click to select the word under the {mouse pointer}.
     
        (1997-03-21)