"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".
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.)
The occasionally held belief that the "X" represents the cross on which Christ was crucified also has no basis in fact. St Andrew's Cross is X-shaped, but Christ's cross was probably shaped like a T or a †. Indeed, X-as-chi was associated with Christ long before X-as-cross could be, since the cross as a Christian symbol developed later. (The Greek letter Chi Χ stood for "Christ" in the ancient Greek acrostic ΙΧΘΥΣ ichthys.) While some see the spelling of Christmas as Xmas a threat, others see it as a way to honor the martyrs. The use of X as an abbreviation for "cross" in modern abbreviated writing (e.g. "King's X" for "King's Cross") may have reinforced this assumption.
In ancient Christian art, χ and χρ are abbreviations for Christ's name. In many manuscripts of the New Testament and icons, X is an abbreviation for Christos, as is XC (the first and last letters in Greek, using the lunate sigma); compare IC for Jesus in Greek. The Oxford English Dictionary documents the use of this abbreviation back to 1551, 50 years before the first English colonists arrived in North America and 60 years before the King James Version of the Bible was completed. At the same time, Xian and Xianity were in frequent use as abbreviations of "Christian" and "Christianity"; and nowadays still are sometimes so used, but much less than "Xmas". The proper names containing the name "Christ" other than aforementioned are rarely abbreviated in this way (e.g. Hayden Xensen for the actor name "Hayden Christensen"). This apparent usage of "X" to spell the syllable "kris" (rather than the sounds "ks") has extended to "xtal" for "crystal", and on florists' signs "xant" for "chrysanthemum (though these words are not etymologically related to "Christ"; "crystal" comes from a Greek word meaning "ice"; "chrysanthemum" comes from Greek words meaning "golden flower"; "Christ" comes from a Greek word meaning "anointed").
In the 17th and 18th Centuries, "Xene" and "Exene" were common spellings of the given name Christene.