noun. In pathology, a localized dilatation of an artery, due to the pressure of the blood acting on a part weakened by accident or disease.

noun. In thermometry, an enlargement of the capillary tube of the thermometer.

noun. A soft, pulsating, hollow tumor, containing blood, arising from the preternatural dilation or rupture of the coats of an artery.

noun. Alternative spelling of aneurysm.

noun. a cardiovascular disease characterized by a saclike widening of an artery resulting from weakening of the artery wall

"Or this line, after Wolowitz invited his date over for Shabbat dinner: “A Catholic girl like you wearing a big cross like that might just give my mother the big brain aneurism I’ve been hoping for.”"