A dreidel is a four-sided top used for play during Hanukkah. The four sides each show a different character: nun, gimel, hey and shin.
The game played with a dreidel is a simple betting game, with each of the sides of the top indicating what the player who spins must do. Each player starts with a small amount of whatever currency is being used for the game, be it pennies, small candies or some other token. At the start of a player's turn, he places one token in the collective pot, then spins the dreidel.
If the dreidel lands with nun facing up, the player does nothing and play proceeds to the next player. If it lands on gimel, the player takes the entire pot for the turn. If it lands on hey, the player takes half of the pot, and if the dreidel lands on shin, the player puts a small number of tokens into the pot.
A popular apocryphal history for the dreidel holds that the game originated in the time of the Greek-Syrians. During this period the Jewish people were barred from studying their Torah by the Greek-Syrians. Legend has it that as a way to justify gathering for Torah readings, Jewish people would keep a dreidel around so if any Greek-Syrians came by they could hide the Torah and act as though they were merely playing a game. A similar account holds that the dreidel acted as an excuse to gather for discussions of the Torah, which would take place while spinning the top.
A more likely origin of the dreidel has it connected to an English and Irish top game of a very similar nature. This game, called teetotum or totum, was played throughout the 16th century. The letters used on the totum top were N for "nothing", T for "take all", H for "take half" and P for "put in". When the game made its way to Germany, the letters changed to N for nichts meaning "nothing", G for ganz meaning "all", H for halb meaning "half", and S for stell ein meaning "put in". When Yiddish speaking German Jews began playing the game, they used the Hebrew letters which made the same sounds and the accompanying words: nischt, gantz, halb and shtel.
The letters used on the dreidel are also used to represent the words "nes gadol haya sham" meaning "a great miracle happened there." Since the creation of the Israeli state in 1948, there has existed a slight variation, substituting the letter shin with the letter pay and changing the phrase to "nes gadol haya po" meaning "a great miracle happened here."
A teaching in the midrash indicates that the four sides of the dreidel, in addition to their representation of the above phrase, also represent the four major ancient kingdoms which attempted to exterminate the Jews. This has nun representing Nebuchadnezzar and his kingdom of Babylonia, gimel representing Gog and the kingdom of Greece, hay representing Haman and the kingdom of Persia, and shin representing Se'ir and the kingdom of Rome.
The dreidel is also known as a fargle or varfl in Yiddish, and as a sevivon in Israel.