The letter X seems to be everywhere these days, appearing in places a bit confusing (for example, Elon Musk’s Twitter), secret (the X on the treasure map), or even unknown (algebraic X). But the one place that X has long been misinterpreted and misunderstood, despite its surprisingly long history, is in the popular short-form of the Christian holiday otherwise known as Xmas.

Where does the mysterious Xmas even come from and what does it mean?

Ancient history

The letter X comes from a Phoenician letter known as samekh, which was originally used to represent an “s” sound. The samekh symbol would hardly be recognizable to a modern speaker as an “x,” given it took the form of three short horizontal lines crossing over a single vertical line. But, around 800 BCE, the Greeks borrowed the Phoenician alphabet and modified the symbol to something more X-like, and called it chi.

In Greek, chi was used to represent the sound “k” or, later, “ks,” which is the sound combination we often pronounce whenever we use an “x” in English (as in tax). Around 700 BCE, the ancient Greeks established a strong trade with the Etruscans who inhabited Italy, bringing their alphabet alongside wine, perfume, and other goods they were hawking. Since the Etruscans did not have a writing system of their own, the Greek alphabet came in handy.

There was also a separate group, the Romans, who lived under Etruscan rule and, though they spoke a different language (Latin), they too adopted the alphabet borrowed from the Greeks. By about 300 BCE, they managed to overthrow the Etruscans, but kept the alphabet, making some modifications that made the letters look much more like what we use today.

Getting to the “x” in x-mas

Though many feel that using “x” in x-mas is a disrespectful way to refer to Christmas, history reveals a new side of the story. It seems that the “x” that we use in x-mas is not at all recent but instead comes from the letter’s Greek and Roman history.

In Greek, the word Christ, meaning “the chosen one,” was written as Χριστος (translating as “Christos”), with “x” as the first letter of the word. And, in the 3^rd Century, it was common to write sacred names using abbreviations that made those holy names stand out more in a manuscript.

Chi-Rho

Source: Dragovit, CC BY-SA 4.0 Creative Commons license/Wikimedia Commons

One of the earliest shortenings for Christ was XP, also known as “chi-rho,” based on the first two letters in the Greek name (x and p, the Greek symbol for r). It is said that the 4^th Century Roman Emperor Constantine dreamt that he would be victorious in an upcoming battle if he paid tribute to Christ by emblazoning his soldier’s uniforms with the“chi-rho” symbol, for example, XP, in his honor. It turned out to be a good call since Constantine won the battle and is remembered today as Constantine the Great.

This abbreviation became a common way to write the name of Christ, and its subsequent shortening to X was very likely related to scribal practices in the intervening centuries. By the mid-1500s, x-mas started to be used as a shortened form of the Anglo-Saxon word, Christemasse, meaning the celebration or festival of Christ.

X marks the holiday

Since “x” stands for Christ, “x-mas” should not be viewed as an insulting or secular term. We also see references dating back to the same period using “x” in the word xtian, meaning Christian, and xtianity, meaning Christianity.

Over time, however, the religious meaning of the letter seems to have become less well-known, which is why people often fail to recognize the deep religiosity behind the term “x-mas.”

The many modern uses of the letter x – particularly for standing for things unknown or mysterious – have obscured the early history of this letter, but whether used for Xmas or the X-files, its power rests in its ability to change and morph to meet the needs of those who use it.