noun
also an·eu·rism ˈanyəˌrizəm
( -s )
Etymology: Greek aneurysma, from aneurynein to dilate, from ana- + eurynein to stretch, from eurys wide — more at eury-
: a localized abnormal dilatation of a blood vessel (as an artery) filled with fluid or clotted blood, usually forming a pulsating tumor, and resulting from disease of the vessel wall