aneurism, aneurysm

[In Fr. anévrisme, anévrysme; Sp. & Port. aneurism a; Gr. ἀνεύρυσμα ( aneurusma ), and ἀνευρυσμός ( an eur us mos ), from ἀνευρύνω ( aneuruno ) = to widen, to open; εὐρύνω (euruno) = to make wide or broad; εὐρυς ( eur us ) = wide, broad.] Med. A morbid dilatation of the aorta, or one of the other great arteries of the body. Four varieties of this malady have been described. In the first the whole circumference of the artery is dilated; in the second, or true aneurism, the dilatation is confined to one side of the artery, which then takes the form of a sac; in the third, or false aneurism, the internal and middle coats of the artery are ulcerated or ruptured, while those which are external or cellular expand into a sac; in the fourth, or mixed variety, the false supervenes upon the true aneurism, or upon dilatation. ( Dr. J. Hope , Cyclo. Pract. Med ., vol. i., p. 104)