1580s, of imitative origin (cf. Dutch and East Frisian klikken "to click; Old French clique "tick of a clock"). The figurative sense, in reference usually to persons, "hit it off at once, become friendly upon meeting" is from 1915, perhaps based on the sound of a key in a lock. Related: Clicked; clicking.
1610s, from click (v.). Click-beetle attested from 1830.
click (klĭk)
n.
A slight sharp sound, such as that heard from the heart during systole.
hardware
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". Multiple clicks in quick succession, e.g. a double-click, often have a different meaning from slow single clicks. 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)