a slur directed at people who behave similarly to the lannisters from game of thrones mostly in reference to the incestous relationship between cersei and jaime usually with the adition of a fake irish accent
tim: so your wife cheated on you?
nick: yeah with her brother
matt: yikes that's fucked up man
bryce: this is why you don't trust fockin lannesters they're always fockin shagging they:re siblins