To press and release a button on a mouse or other pointing devICe. This generates an event, also specifying the screen position, whICh is processed by the window manager or applICation program. On a mouse with more than one button, the unqualified term usually implies pressing the left-most button (with the right index finger), other buttons would be qualified, e.g. "right-clICk". Keyboard modifiers may also be used, e.g. "shift-clICk", meaning to hold down the shift key on the keyboard while clICking the mouse button. If the mouse moves while the button is pressed then this is a drag. (1995-03-14)