CLARKSBURG, W.Va. (WBOY) — Have you ever seen a decoration or a sign labeled as “Xmas” instead of “Christmas” and wondered why? There’s an answer for that, and it’s a bit older than you may think.

Contrary to popular belief, Xmas is not a way of shortening the word to save space nor is it an attempt to remove “Christ” from the word — quite the opposite actually.

According to Dictionary.com, the use of Xmas first started in the mid-1500s as just another way of writing it. X wasn’t meant to be read in the “ecks” way we say it in English today but was rather meant to be read in its Greek form, “chi.” Chi is the first letter of the Greek word Χριστός (Christos), which translates to (Jesus) Christ.

X was adopted as a way of representing Christ across languages, considering all of the ways it can be written. Other less common abbreviations using this style are Xpian and Xtian, which both represent the word Christian.

Even in its first marked usage, the X abbreviation was nothing new as Greek letters have been used to identify Christians since the age of the Roman Empire.

According to U.S. Catholic, Christians in the Roman Empire often used the Chi-Rho (☧) symbol to mark their tombs where they worshipped and any other locations they deemed important. Chi-Rho is simply a stylized combination of the Greek letters chi and rho which are the first two letters of Χριστός.

The use of the Chi-Rho carried on through the fall of the Roman Empire and is still used by Eastern Orthodox Catholics to this day.