Definition of X
In the written terminology of various arts and trades, where two or more dimensions of the same piece or article are to be stated, this letter is a well-known symbol equivalent to the word "by.” Thus, the formula "3 x 5 in.” will be understood, or may be explained by parol evidence, to mean "three by five inches,” that is, measuring three inches in one direction and five in another.
A mark used in place of a signature by one who is unable to otherwise affix his or her signature. See Mark. Symbol used in financial newspapers to indicate that a stock is trading ex dividend (i.e. without dividend).
That's the definition of X in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.
