A British term that means "in big trouble" or "trouble that will result in death" though the first one is more common.
This term isn't that commonplace in Britain anymore but still is used in extreme situations.
"You sir are in grave danger if you don't let me pass this door that leads in to the pub"
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi