What is a hooley? Where does the word come from?

Everything about the word hooley is disputed, including the spelling.

Is it Hoolie or hooley? Or even huly? This was as it first appeared Bartlett's Dictionary of American English in 1877.  

A hoolie is now a generic term for a raucous party. The word is most commonly used in Ireland, but it can be traced back to Orkney Scots.

The Scots hooley meant a strong wind or gale. This sense is still apparent in the idiom blowing up a hooley.

Irish Words in English