Merry Christmas and happy holidays, everyone! It’s holiday fun fact time again. This time a simple etymology tidbit about the word “Christmas” or “Xmas”.
The word Christmas originated as a compound meaning “Christ’s Mass”. It is derived from the Middle English Christemasse and Old English Cristes mæsse, a phrase first recorded in 1038.[8] “Cristes” is from Greek Christos and “mæsse” is from Latin missa (the holy mass). In Greek, the letter Χ (chi), is the first letter of Christ, and it, or the similar Roman letter X, has been used as an abbreviation for Christ since the mid-16th century.[16] Hence, Xmas is sometimes used as an abbreviation for Christmas.
From: http://en.wikipedia.org/wiki/Christmas