1. Fuck that, fuck you 2. an expression to say when something happens thats wack, uncalled for or just plain stupid.
3. an interjection to yell when something happens that you wish didn't
It basically means (boy) or (Hey boy). My grandparents were born in Italy and came through Ellis Island around 1913. My Father used to say it to me when I was young all the time. I now use it as a term of endearment towards my youngest son.