Why do people sometimes substitute x for letters in a word?


  • Xing
  • Xmas
  • Xfr
  • A couple of others: tx = transmit and rx = receive, both indicating a crossing of a message or signal.
    – Hugo
    Dec 20, 2011 at 9:11
  • or eXchanging of messages (Rx,Tx) or Transformers (Trans=cross over) or X-ForMeR or XFMR Oct 8, 2018 at 21:21

4 Answers 4


In those three examples, there are three different, albeit related, reasons:

  • Xing = Crossing. The "X" replaces "Cross" because an X is a cross.

  • Xmas = Christmas. The "X" replaces "Christ" because the cross is a symbol of Jesus and because X (really Chi) is an initial for "Christ" in Greek (Χριστός).

  • Xfr = Transfer. The "X" replaces the prefix "trans-" as it implies a crossing of something.

They are all abbreviations. I would be surprised if the origin of "Xing" wasn't in street signs, where "crossing" would be a long word to print to be able to read at a distance. I've more often seen "Xfr" as "Xfer"; it is used in electronic communications as jargon. I don't know the origin of "Xmas", but some people would have you believe that it's an effort to remove Christ from the holiday. I would guess it is just another general abbreviation.

  • 1
    Probably shouldn't get into the whole "war on Christmas" thing, but I'd like to point out that I remember my mom explaining the X in Xmas to me when I was a little kid back in the early 70's. If its a nefarious plot, its a very old one.
    – T.E.D.
    Aug 9, 2011 at 22:22
  • 6
    Xmas goes way back. Google Books quickly showed this use published in 1791 but quoting a letter from 1719.
    – mgkrebbs
    Aug 9, 2011 at 23:22
  • And the older X'temmas goes back to at least 1551.
    – Hugo
    Dec 20, 2011 at 9:08
  • 4
    @mgkrebbs: X as an abbreviation for Christ goes even further back than that: 16th century English church registers often wrote "Christopher" as Xtopher or similar. See for example: ellipsis.cx/~liana/names/english/parishes/parishes.html -- I can't figure out how people add links to comments. It's not taking straight html.
    – JPmiaou
    Dec 22, 2011 at 5:19
  • 1
    @JPmiaou [Words for link]REMOVE_THIS_To_make_the_bracketed_text_a_link_to(THIS_URL). Oh, and +1 for pointing out that Xmas is not a demonic plot. Not to say anything about rampant consumerism...
    – user14070
    May 11, 2012 at 15:31

X is sometime used as a replacement target in technical document. Example:

Conditional jumps instructions (Z if zero, A if above,...)
JX : where X can stand for one of the value above.

Which means that Jx is actually either JZ,JA,... But it's a very rare case, I admit.

  • 2
    The question wasn't "what are some examples of using X to abbreviate word?" (such a question would be off-topic, anyway); the question was "why are some words abbreviated using X?".
    – Marthaª
    Jul 19, 2013 at 15:18

Xmas is a specific case of using X to denote Christ, a practice that goes back many centuries. One can look up further details, but essentially it's an initial. Imagine if you were documenting the daily activities of the President of the United States, lots and lots of things Barack Obama said and did. Especially if you were writing it out with a quill pen, you might quickly start abbreviating using B to mean Barack Obama. "Secret service guarding B cautioned. .."

  • Many such writing abbreviations were used when everything had to be written out by hand (like modern textspeak). "Y" for "th" is another example (as in "ye olde...") because an obsolete letter representing the sound th looked a bit like a y. Jul 12, 2016 at 14:35
  • POTUS and SOTUS agree Oct 8, 2018 at 21:23

Several abbreviations including X came to common language from Morse code, most notably TX and RX for "Transmit" and "Receive". Other examples include VX for "Voice", NX for "Noise" and DX for "Distance".

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