Alot of people use the phrase for terms of shortness and don't actually know what it means but, the Greek letter X (chi) is the first letter of the Greek word for Christ, Xristos ( ???????) so Xmas therefore means "Christ's Mass" which is what the word Christmas actually means.
In Greek, the original language of the New Testament, the word for "Christ" is xplotoc, which begins with the Greek letter that is essentially the same letter as the English letter X. So, originally, Xmas was simply an abbreviation of Christmas. No grand conspiracy to take Christ out of Christmas. Just an abbreviation.
1 year ago
Last edited at 7:55PM on 12/19/2012
As others have pointed out, X stands for the first letter of "Christ" in Greek, in the sense the the English X stands for the Greek Chi. It looks the same anyway. For this reason Jewish people don't put an x when then need to mark a box, and put a v instead. They don't want to even casually and inadvertently suggest his name.