Meaning of BUTTON in English

Small disk or knob used as a fastener or ornament.

It usually has holes or a shank through which it is sewn to one side of a garment. It is used to fasten or close the garment when it is passed through a loop or hole in the other side. The ancient Greeks fastened their tunics with buttons and loops. In medieval Europe, garments were laced or fastened together with brooches or clasps until the buttonhole was reinvented in the 13th century. Throughout history, buttons have been made in a range of sizes and materials, some elaborated into miniature works of art.

Britannica English dictionary.      Английский словарь Британика.