A shuttlecock is the small object you hit back and forth in the game of badminton. It has a rounded cork or rubber base with a cone of feathers (or plastic strips) attached to the top. When you strike it with a badminton racket, those feathers make it fly in an unusual way: it spins, floats, and slows down much faster than a tennis ball would.

The design is surprisingly clever. The feathers work like a natural brake, stabilizing the shuttlecock in flight so it always travels cork-first through the air, no matter how you hit it. This gives badminton its distinctive rhythm, mixing lightning-fast smashes with delicate, floating shots.

You might also hear people call it a birdie because of those feathers, though serious badminton players usually say shuttlecock or just shuttle. Professional players can smash a shuttlecock at speeds over 200 miles per hour, making badminton one of the fastest racket sports in the world.