This year, Christmas Eve falls on the third night of Hanukkah and Christmas Day, subsequently falls on the fourth night. Many refer to this combination of holidays as "Chrismukkah."Urban Dictionary defines the holiday as, "The ultimate holiday. A combination of Christmas and Hannukah. Twice the resistance of a normal holiday because Jesus and Moses are on your side." The origin of Chrismukkah is commonly said to be the early-2000s teen drama The O.C., in which Seth Cohen, played by Jewish actor Adam Brody, explains that he created the holiday to celebrate Christmas with his mother, played by Kelly Rowan, and Hanukkah with his father, played by Peter Gallagher.However, the Jewish Museum of Berlin says German Jews in Germany were the first to use the term in the 19th century, according to Alma. The German word was "Weihnukkah," a combination of Weihnachten, the German word for Christmas and Hanukkah. However, the holiday never had a strong following and died out when Hitler came to power, Alma reported.Despite its flimsy origins, Chrismukkah has become almost as much of a commercial and popular holiday as the two that comprise it. There are several free and paid online guides on how to celebrate the holiday. Many of the suggestions blend the holiday traditions. One Jewish Telegraphic Agency article proposes serving egg nog sufganiyot and Hanukkah candy canes.There's also no shortage of Chrismukkah gear available online. Chrismukkah partakers can wear a yamaclaus, a kippah that looks like a Santa hat, while drinking egg nog and eating latkes. There are shirts, cards, mugs and ornaments all dedicated to the combination holiday.