An'ēū-rĭsm, n.

n. [N. Lat. aneurisma, Gr. ἀνεύρυσμα, and ἀνευρυσμός, a widening, an opening, from ἀνευρύνειν, to widen, from ἀνά, throughout, and εὐρύνειν, to make wide, from εὐρύς, wide.] (Anat.) A soft, pulsating tumor, arising from the preternatural dilatation or rupture of the coats of an artery.