Used to describe a total and complete retard, P.O.H. standing for Pants-On-Head. This is the highest level of idiocy one can achieve, and use of the term epic fail while calling said moron out is encouraged, because it is the only term known to man that can do justice to the stupidity of the action. It's that bad.
Moron: I'll be making 100,000,000,000 dollars when i patent my solar powered flashlight! Haha!
Guy 1: Wow, he's frigging POH retarded.
Guy 2: Epic Fail.