why is christmas called christmas

Christmas is called Christmas because it is named after the ancient Greek word for Christ, "Christos." The holiday is also referred to as "Xmas" due to the Greek letter "chi" which is the first letter in the word "Christ." The word "Christmas" was first used in the English language in the 11th century. It became a common term for the celebration of the birth of Jesus Christ, who was born on December 25th. The name "Christmas" is now used worldwide to refer to this special day.