Xiphisternum :: Xiphisternum (n.) The posterior segment, or extremity, of the sternum; -- sometimes called metasternum, ensiform cartilage, ensiform process, or xiphoid process..
Xiphius :: Xiphius (n.) A genus of cetaceans having a long, pointed, bony beak, usually two tusklike teeth in the lower jaw, but no teeth in the upper jaw..