AN'EURISM, noun [Gr. to dilate, from broad.]
A preternatural dilatation or rupture of the coats of an artery. This is encysted or diffused. The encysted aneurism is when the coats of the artery being only dilated, the blood is confined to its proper coat. Of this kind is the varicose. The diffused aneurism includes all those in which, from an aperture in the artery, the blood is spread about in the cellular membrane, out of its proper course.