aneurism
aneurism (an"u*riz'm) , noun
[Greek 'aney`rysma, 'aneyrysmo`s, a widening, an opening; 'ana` up + e'yry`s wide.]
(Medicine) A soft, usually pulsating, sac, containing blood or blood clot, arising from the abnormal dilation of the walls of an artery, vein or heart. The more common spelling is aneurysm.
Also: aneurysm