Define Mr. X Meaning

Mr X
A secretive person that no one knows

Mr x is annoying
By Eddi
Mr X
Mr. X is the male version of the letter "X" in the English alphabet. Mrs. or Ms. X is the female version. Since they have no genitalia it is hard to differentiate between the two.

By Zondra
Mr X
mister X is a person that you talk about with friends in code, usually a dealer of things that are code-worthy. See Mr. Nice Guy.

Are you going to mr x's? To get that stuff? Cool.
By Laure
Mr Mann X Desi
My otp

Daku: What's your server otps?
Me: Mr Mann X Desi
By Tracy
Mr. X
Mr x is a person who is a threat to the one direction fandom they leave really strange messages and death threats towards the boys. They have been inactive since around 2013 but we still should look out for them.

We need more guards theres been news about mr. X being at a show in 2021
By Daloris