Xmas has been used for hundreds of years in religious writing, where the X is understood to represent a Greek chi, the first letter of Cistoz, “Christ”; in this use it is parallel to other forms like Xtian, “Christian.” But the letter X, or especially x, is nowadays more frequently interpreted as a mathematical variable than as a Greek letter, as indicated by the common pronunciation of the form Xmas as (μks“m…s). Thus, while the word is etymologically innocent of the charge that it omits Christ from Christmas, it is now generally understood only as an informal shortening. In an earlier survey 88 percent of the Usage Panel rejected the use of Xmas in writing.
Xmas 在宗教作品中已用了几百年，X 用来表示希腊字母chi，是Cistoz的第一个字母，意为“耶稣”；在这种用法中，它与其他形式相似,如Xtian, “教会的”。 但是字母X， 尤其是 x， 现在更常见的是当作数学变量，而不是希腊字母，因为该符号Xmas 发音已普遍为(μksm…s)。