(Ok, I lied, one more holiday themed post before I take a break :))
Why do we use the abbreviation Xmas for Christmas?
It originates from the Greek letter chi, which looks similar to an X. Since this letter (X) represented a "k" or "ks" sound in ancient Greek, it was used as an abbreviation for Christ. Though there may be some controversy over the usage of Xmas, it is not meant to be looked at as a way to "remove" Christ from Christmas.
The letter X can also represent "cross" or "trans" as in:
xfer, xlate = transfer, translate
X-out, X-over = cross out, crossover
How do you pronounce Xmas?
Should you try to pronounce the shortened form like "eks-mas" or just say "Christmas"?
Going slightly off topic:
Words that start with vowels usually take "an" as their indefinite article. Of course there are exceptions, like the word university. While it is spelled with a "u", it is actually a "y" sound. Thus, "a" is used and not "an".
We can use this information to find out more about the Xmas pronunciation:
What was mentioned above is a method in determining one's pronunciation of a word based on writing (barring typos). If one writes "an Xmas", they are pronouncing it "eks-mas", even though the written form starts with X, there's a vowel sound initially. Otherwise, for "a Xmas", we can assume "Christmas" is pronounced.
A quick google search reveals the following:
"a xmas" : 455,000 results
"an xmas" : 181,000 results
It seems that the traditional pronunciation for Xmas ("Christmas") is more common.
It would be interesting to know how you pronounce Xmas. Would you say "eks-mas" only in informal settings, or would you not bother with that pronunciation at all?
I'll get back to more topics on phonetics after the holidays :)
In the meantime, have a Merry Christmas and a Happy New Year!