Hardcore old Irish (or at least Boston Irish) curse.
I've heard this curse only once...
A Charlestown guy came into my father's pub in Southie and started trouble while I was there. He was a Navy guy who has just got back from Germany and wanted to sit with some fellow Irishmen. Unfortunately, he sat in "Bud"'s seat. Bud is a big guy in Southie and so my father asked the guy to move. He got pissed and spat at my father. My dad ripped into him, and pushed him off the stool.
Then the Charlestown guy used this doozy on him (while I, his only son was there, which apparently makes it worse).
The guy got away with a broken rip, nose and a black eye. Never use this one in the company of people who are bigger than you.