A foolish person (particularly one that has a propensity for hooliganism) that chronically makes obviously bad decisions, but who also continuously shrugs them off in an "i am livingmy life, don't bother me" kind of fashion.
Nickname given to Red Hot Chili Peppers guitarist John Frusciante presumably by Ultimate-Guitar.com, because that's one of the only places you'll find people calling him Froosh instead of John.
Have you heard Froosh's solo in Scar Tissue at Slane Castle?