A simple device, resembling a button in form, so arranged that pushing it closes an electric circuit, as of an electric bell; -- called also button.
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "push button" in a sentence
"The lock, she saw, wasn’t simply a push button or latch but actually a key-entry-only doorknob, and the madman was now tucking the key comfortably into his pants pocket."