x1 or X Audio pronunciation of "x" ( P ) Pronunciation Key (ks)
n. pl. x's or X's also xs or Xs
1. The 24th letter of the modern English alphabet.
2. Any of the speech sounds represented by the letter x.
3. The 24th in a series.
4. Something shaped like the letter X.
5. A mark inscribed to represent the signature of one who is unable to sign one's name.
6. An unknown or unnamed factor, thing, or person.