Button is described as a small cylindrical die steel with an opening larger than the punch point size, generally by a percentage of the thickness of the material being pierced.
Button pertains to the the cap component of a standard snap fastener closure device which is usually seen sewn in clothes, and functions together with button holes. Button-makers categorized buttons by types of holes, shape, size, and color. The basic shapes of buttons were disc (two-hole and four-hole), ball (half-sphere), geometric (diamond, prism, square, rectangle, and parallelogram), and realistic (animals, flowers).
In fencing, button is identified as the soft covering over the point of a foil or epee. The foil is a thrusting weapon used in competition that allows valid touches only with the tip of the blade, while the epee is a weapon with a blade triangular in Cross-section and heavier than that of the foil. The epee has a large, cup-shaped guard that protects the hand and forearm.