\Xiph"i*ster"num\, n.; pl. {Xiphisterna}. [NL., fr.
Gr. xi`fos a sword + sternum.] (Anat.)
(a) The posterior segment, or extremity, of the sternum; --
    sometimes called {metasternum}, {ensiform cartilage},
    {ensiform process}, or {xiphoid process}.
(b) The xiphiplastron. -- {Xiph"i*ster"nal}a.