mid-13c. (implied in botouner "button-maker"), from O.Fr. boton (Fr. bouton) "a button, bud" (12c.), from bouter, boter "to thrust" (see butt (v.)). Thus a button is, etymologically, something that pushes up, or thrusts out. The verb is late 14c.
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
button in Technology
1. push-button. 2. A graphical representation of an electrical push-button appearing as part of a graphical user interface. Moving the mouse pointer over the graphical button and pressing one of the physical mouse buttons starts some software action such as closing a window or deleting a file. See also radio button. (1997-07-07)