When, in the game of chess, you make a move that allows your opponent to mate you on the next turn.
I thought I could take his rook for free, but I was hanging the king
Apart from the original Richard Keys usage of the phrase, to hang out the back of something can be used as an expression of approval of something well done.
(after eating a good meal cooked by a friend) "that pasta was great, you really hang out the back of it"
Posture of the head showing its crown with the chin to the chest. The head may be hung to one side. The posture denotes a spiritual, emotional, mental or physical state of distress.
Hangs head in misery:
She ditches him in his third year and he hangs his head in misery at the table and in class... Best gift ever! That bitch's cunt stunk like a fish processing plant.
To stand around with nothing to do whatsoever.
The doors don’t open until 10, so we’ll just hang balls until then.
taking your girlfriend while she is sleeping and hanging her upside down and face fucking her.
"Dude you have to try the hanging bat on your girl."