Xmas or Christmas

Jane overheard a couple of ladies the other day - one said to the other, "I #@%ing hate it when people say X-mas, why can't they say CHRISTMAS for crying out loud!"
Well, here's an explanation from Panatti's Extraordinary Origins of Everyday Things:

The familiar abbreviation for Christmas was originated with the Greeks. X is the first letter of the Greek word for Christ, Xristos. By the sixteenth century, "Xmas" was popular throughout Europe. Whereas early Christians had understood that the term merely was Greek for "Christ's mass," later Christians, unfamiliar with the Greek reference, mistook the X as a sign of disrespect, an attempt by heathen to rid Christmas of its central meaning. For several hundred years, Christians disapproved of the use of the term. Some still do.

Merry Xmas, folks!