Cats Ass
The alternative definition to "cats ass" as indicating something quintessentially cool. In this definition, cats ass is used to denote a small circular bald spot on the back of a mans head that is surrounded by dense hair and thus resembles a felines anus. The term can also be used to indicate any small circular void of something that was previously present and now missing, as long as it resembles it's namesake - a kitties butthole (e.g., a small round patch of dead grass in an otherwise healthy lawn). But let's be honest , its best used to harass your balding friends.