Beaut

n.

Heard in Cork, Kilkenny, Sligo and Kerry

One who's unbelievable in a bad way. eg, one who's left the side down on purpose or without thinking.

In use

What, you missed the penalty on purpose? Jaysus, you're a pure beaut, boy!

Posh English

Good heavens, you missed the penalty deliberately? You are a remarkably foolish fellow.

Same phrase, other counties