What is Y-shaped Coffin?
1.
To bury in a Y-shaped coffin. British pejorative term for a lady of questionable virtue. Originates from the idea that the subject is such a down-and-out slut that her legs part so much that they'd be stuck like that if she was to die.
"Bloody Hell, Alex, don't you reckon Bernadette would be buried in a Y-shaped coffin?
2.
An indirect term for a sexually promiscuous girl. To be buried in a Y-Shaped Coffin would imply that the girl never had her legs closed, and a coffin had to be built to suit these parameters. It's fucking hilarious is what it is.
Edmund: This is THE Jane Herrington???
Percy: Yes.
Edmund: Jane - bury-me-in-a-Y-Shaped Coffin - Herrington?
See
3.
A term referring to a coffin specially made for a person who died with their legs spread wide. Such a person had presumably died during a sexual act and rigor mortis had set in before the victims legs could be closed.
Yeah, he's such a whore he'll be buried in a Y-shaped coffin.
See