Several years ago a friend of mine and I were discussing words, and wondered whether there was a word that described a word which, when spelled backward, spelled another word. A palindrome, of course, is a special case of such a word, but we couldn't find a word to describe the general case of simply being a word when spelled backward. So we coined one - drow - but didn't at the time, and still don't, have the foggiest notion as to whether we re-invented the wheel or came up with an original. Does any wordsmith out there know whether there's already a word for such a word?