As a noun, someone considered likely to commit suicide, someone who has attempted committing suicide in the past or made plans to, etc. Used to describe people who are actually serious about it, or people who are probably serious about it but haven't revealed it to anyone just yet.
Derived from the picture depicted on the
King of Hearts face card included in a deck of
52 cards. In most basic
decks, the King is shown holding a sword horizontally behind his head, making it look as if he's stabbing himself through the head.
In a verb sense, to pull a
king of hearts would mean to commit suicide, or try to.
---
"Oh god, I think I just flunked, I forgot about that friggin test! My parents are gonna kill me! Maybe I should just do the job for them"
"Hey,
chill man, it was just a math test. Ask to
retake it or something, or deal with it, you're no
king of hearts"
