I'm almost finished with Robert Ludlum's novel THE ICARUS AGENDA, which has two slang phrases in it that have me scratching my head (a lot). "A two toilet Irish detective" is supposed to be American Boston-Irish slang, and I guess isn't too hard to figure out. I still wanna know!
1.Used to take the piss out of an individual who thinks their hard.
2.Also can be used as a term of endearment, in a similar fashion to " boi" or " boss"