X is also used as a substitute for the most things that sounds similar to "cross." This is because the representation of the letter X looks like two sticks crossing each other's path. This abbreviation is commonplace as it is easier than writing the whole 4-5 letter "cross." (It does not speak well for the human race that we don't even have time to write "cross" down). Examples include:

- Xmas (Christmas)

- Xing (Crossing )

- Xover (Crossover)