this has a number of different meanings:
1) Can be used as a general greeting of an odd, interesting, and/or manically behaving individual.
2) Or as a cry of disbelief or shock, usually after an unthoughtful or an over-provocative comment, sometimes sexual in nature.
1) Person1: Hello! Nice to meet you. My name is (insert name). Yours?
Hoonamoona Balloonamoo, which means the lover of all things four-legged and hairy, yet human-like.
You...are a Malone.
What'd you do last night?
I had a three-way with your mother and 70 year old aunt...