Tennis Buttock

• aft, stern and poop, naval in origin; in nautical jargon, buttocks also designates the aftermost portion of a hull above the water line and in front of the rudder, merging with the run below the water line
o apple (bottom), referring to the similar shape of the fruit, derived from the 1970s. Also likened to an upside-down heart, attributed from various, popular ads of the '70s.
o caboose, originally a ship's galley in wooden cabin on deck; also the "rear end" car of a freight train, considered a cute synonym suitable for any audience