The word "Christ" and its compounds, including "Christmas", have been abbreviated in English for at least the past 1,000 years, long before the modern "Xmas" was commonly used. "Christ" was often written as "XP" or "Xt"; there are references in the Anglo-Saxon Chronicle as far back as AD 1021. This X and P arose as the uppercase forms of the Greek letters χ and ρ), used in ancient abbreviations for Χριστος (Greek for "Christ"), and are still widely seen in many Eastern Orthodox icons depicting Jesus Christ. The labarum, an amalgamation of the two Greek letters rendered as , is a symbol often used to represent Christ in Catholic, Protestant, and Orthodox Christian Churches.
Nevertheless, some believe that the term is part of an effort to "take Christ out of Christmas" or to literally "cross out Christ"; it is seen as evidence of the secularization of Christmas, as a symptom of the commercialization of the holiday (as the abbreviation has long been used by retailers). It may also be seen as a vehicle to be more inclusive. (See political correctness.)

"Xmas" and "X-mas" are common abbreviations of the word "Christmas". They are sometimes pronounced "eksmas", but they, and variants such as "Xtemass", originated as handwriting abbreviations for the pronunciation "Christmas". The "-mas" part came from the Latin-derived Old English word for "mass".