term:

X

x n

often cap
1 : a mark used in place of a signature when the maker is incapable of signing his or her name (as because of illiteracy or a physical ailment)
2 : a mark used in indicating a choice or applicable item (as on an insurance form)
abbr 1 ex-distribution
2 ex-dividend
3 ex-rights
4 ex-warrants

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.