To quote Demitri Martin (taken from this session at around 0:57):
When there's someone who's dead and then someone does something that that person would not have liked, they say that that person is spinning in their grave. But I don't understand why they say that; why is spinning the way that a corpse shows disapproval? […] If we showed disapproval like that when we were alive, that would make more sense.
Where did this expression spinning in his grave come from? Did it originate in English, or did it come in from another language or culture?
Best Answer
It may come from the gravestone inscription "rest in peace". This was originally meant to refer to the spirit, but was later interpreted as the body resting in peace.
http://en.wikipedia.org/wiki/Rest_in_peace
It follows that a dead person who not resting at peace will move around in their grave like a restless sleeper. The idea of "spinning" in their grave is a comic exaggeration.