A dreidel is a four-sided "top" which can be made to spin on its pointed base. Each side of a dreidel has a Hebrew letter shown on it. The letter's side means "nun", "gimmel", "hay", or "shin". The letters together mean "a great miracle occurred there".
Dreidels are used during the Jewish holiday "Hanukkah" to play a popular children's game that involves betting on which letter will be showing when the dreidel stops spinning. Children usually play for chocolate coins covered in gold-colored foil (called "gelt"), but they can also play for nuts, candy, and raisins.
Dreidels are normally made of wood or plastic, but can also be made of silver and glass. Any number of children can play the dreidel game, but once a child runs out of "gelt" they are out.