aneurysm

American  

[an-yuh-riz-uhm] / ˈæn yəˌrɪz əm /

Or aneurism

noun

Pathology.

1. a permanent cardiac or arterial dilatation usually caused by weakening of the vessel wall.

---

aneurysm British  

/ ˈænjəˌrɪzəm /

noun

1. a sac formed by abnormal dilation of the weakened wall of a blood vessel

---

aneurysm Scientific  

/ ăn′yə-rĭz′əm /

1. A localized, blood-filled dilation of a blood vessel or cardiac chamber caused by disease, such as arteriosclerosis, or weakening of the vessel or chamber wall. A ruptured aneurysm results in hemorrhage and is often fatal.

---

Other Word Forms

• aneurismal adjective
• aneurismally adverb
• aneurysmal adjective
• aneurysmally adverb

Etymology

Origin of aneurysm

First recorded in 1650–60; from Greek aneúrysma “dilation,” equivalent to aneurys- (variant stem of aneurýnein “to dilate,” from an- an- ³ + eurýnein “to widen, broaden”; eury- ) + -ma, noun suffix

Explanation

Sometimes an artery wall weakens in a spot, causing a pouch-like bulge of pooled blood called an aneurysm. If it bursts, it can be life-threatening. While aneurysms can form anywhere, they are most common in the brain and cardiac areas. This is a very serious medical event that can cause injury and even death. Even though aneurysms are potentially deadly, people use the word sometimes in exaggerations. For example, if you see that someone is getting mad, you might say, "Don't have an aneurysm about it!" That just means something like "Take it easy! Don't get so excited."

Example Sentences

Before her aneurysm, Sharon didn’t make time for fiction.

From The Wall Street Journal • Mar. 11, 2026

The registered nurse, who is on maternity leave after having her son Albie, was diagnosed with a brain aneurysm - a swollen blood vessel - after suffering extreme headaches.

From BBC • Jan. 19, 2026

Doctors found that he had suffered a subarachnoid hemorrhage resulting from a ruptured brain aneurysm.

From Slate • Dec. 8, 2025

Kardashian reacted with visible shock, saying the results “explain a lot” about her stress levels as she juggles a sprawling business empire, law studies, an aneurysm recovery, and a highly public personal life.

From Salon • Nov. 29, 2025

But Mrs. Shoemaker wasn't only a substitute teacher, the one who’d taken over for Mr. Nossik after his unfortunate aneurysm, she'd also been Monica Fassbinder's host mother.

From "100 Sideways Miles" by Andrew Smith