PMX 

A maniac. One who cannot control themselves in a public situation. One who wears a pink shirt out in public and strikes out in a blind rage when someone comments on it.

He has had too much to drink. He bumped into that guy purposely to start a fight. He is a PMX.

PMX by LOTB November 29, 2003

PMX 

Like PMS, but a much fiercer, nastier, extreme version.

Dude, your girlfriend looks like a bloated Mike Tyson. Must be the PMX.

PMX by dolphinfan55 August 19, 2009