What Does X Mean?

X means "Kiss" and can also mean "Variable" (in Math).


The letter X is widely used at the end of text messages and emails to signify a "Kiss." It can be typed in either uppercase (X) or lowercase (x) without significantly altering its meaning. However, uppercase may sometimes be used to provide emphasis (i.e., to signify a big kiss).

The use of a single X at the end of a message should not always be regarded as a sign of particular affection. It is often included just to add a warm tone to a message, or simply out of habit. In fact, the inclusion of a single X at the end of a message is so common amongst friends, that not including one may be considered a snub or an indication that the sender is annoyed. (For a table showing the possible meanings of Xs at the end of a message, check out our page on XX (Kisses).)


The letter X is often used in math to mean a value that is not yet known. It is called a "Variable." For example, in X - 3 = 9, X is the "Variable" (which, in this case, equals 12).

Of note: A "Variable" doesn't have to be indicated by the letter X. It could be any other letter, word or symbol.

Image for X

When I write X, I mean this: meaning of X X is also used in math to indicate a "Variable."

Summary of Key Points

First Definition for X

"Kiss" is the most common definition for X on Snapchat, WhatsApp, Facebook, Twitter, Instagram, and TikTok.
1: Easy to guess
Typical Users:
Adults, Teenagers, and Under 13s

Second Definition for X

"Variable" is common definition for X in math.
1: Easy to guess
Typical Users:
Adults and Teenagers


Examples of X in Sentences

Here are examples of X being used in conversations:
  • Gill: Okay. See you there.
  • Jo: Don't be late! X
  • (Here, X means "Kiss.")
  • Gail: If X plus me equals 100%, what's the value of X?
  • Jon: Me?
  • Gail: Correct! XXX
  • (Here, X means both "Kiss" and "Variable.")

An Academic Look at X

In the Middle Ages, most people were illiterate and could only write the letter X. As a result, many people signed letters and sealed envelopes with an X, which they then kissed as a sign of faith and honesty. It is generally accepted that this X represented the Christian cross. However, it is also thought that the X may have represented the name of Jesus Christ, deriving from "ΧΡΙΣΤΟΣ" (which is the Greek word for Christ).

If the X represents a cross, it would be classified as a symbol, rather than a letter. However, if it represents the name of Jesus Christ, it would be a letter. In which case it would be an initialism abbreviation.

What Did We Say before Texting and Social Media?

The use of the letter X to represent a kiss long pre-dates the digital era.

Example of X Used in a Text


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