button
noun
°A knob or disc that is passed through a loop or (buttonhole), serving as a fastener.
"April fastened the buttons of her overcoat to keep out the wind."
°A mechanical device meant to be pressed with a finger in order to open or close an electric circuit or to activate a mechanism.
"Pat pushed the button marked "shred" on the blender."
verb
°To fasten with a button.