Definition of Ex

A latin preposition meaning from, out of, by, on, on account of, or according to.

A prefix, denoting removal, cessation or former. Prefixed to the name of an office, relation, status, etc., it denotes that the person spoken of once occupied that office or relation, but does so no longer, or that he is now out of it. Thus, ex-mayor, ex-partner, ex-judge.

A prefix which is equivalent to “without,” “reserving," or “excepting.” In this use, probably an abbreviation of “except.” Thus, ex-interest, ex-coupons, ex-dividend.

Also used as an abbreviation for “exhibit.”

That's the definition of Ex in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.