"characterized by the use of push-buttons," 1945, originally of military systems, earlier "operated by push-buttons" (1903), from push-button (n.), 1865, from push (v.) + button (n.). Earlier was press-button (1892), from the noun (1879).
purveyor
purview
pus
Pusey
push
push-button
pusher
pushmi-pullyu
push-off
pushover
push-up