Christmas is written as "Christmas" in English. It is derived from the Old English word "Cristesmæsse," which means "Mass of Christ." In other languages, the spelling and pronunciation may differ, such as "Navidad" in Spanish, "Noel" in French, and "Weihnachten" in German. The word "Christmas" refers to the holiday celebrating the birth of Jesus Christ, which is observed annually on December 25th in many countries around the world.