vesuvius said:Ian2 said:*snip*
In Britain, the nether region of ones posterior in the region commonly known as the buttocks is referred to as arse, across the pond however there are sayings like "your * is grass".
One could never image one saying "your arse is grass" in Received Pronounciation, but rather the Phonetic and more common version.
I think its a Potato Putarto thing (interestingly 'Your Arse is Grarse' works phoeneticaly over here - though I've never heard anyone use that expression).
Over here an * is a cross between a horse and a donkey.