In the run up to Christmas last week I'd been pondering where the abbreviation Xmas came from and today's ABC Wednesday is the perfect excuse to find out a little more. According to the entry about Christmas in Wikipedia:
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. "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. Hence, Xmas is sometimes used as an abbreviation for Christmas.
My parents and school always suggested using the word Xmas was rather vulgar and such was this air of disapproval dinned into me from an early age, even today I find it rather a difficult word to use!