Pericardium - definition of pericardium by The Free Dictionary
Medical Encyclopedia Wikipedia per·i·car·di·um (pĕr′ĭ-kär′dē-əm) n.pl.per·i·car·di·a(-dē-ə) The membranous sac filled with serous fluid that encloses the heart and the roots of the aorta and other large blood vessels. ...