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.

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aneurysm British  

/ ˈænjəˌrɪzəm /

noun

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

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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.

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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”; cf. 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

She died from a brain aneurysm in 1974, at the age of 41, just one year before Williams’ career catapulted with “Jaws.”

From Los Angeles Times • May 4, 2026

He said he was on the sofa watching rugby and saw the players "falling off the screen", so headed to the hospital where doctors told him he had a brain aneurysm "that started to leak".

From BBC • Mar. 29, 2026

Sarah, the ex-girlfriend who perhaps knew him most intimately closest to his aneurysm, told Slate she never spoke to him about whether he would want to stay alive in a vegetative state.

From Slate • Dec. 8, 2025

Thomas wanted a share of a multimillion-dollar medical-malpractice award they had won after Joe Brown died of an undiagnosed aortic aneurysm.

From The Wall Street Journal • Nov. 30, 2025

It appeared that Charlie was having an aneurysm.

From "Twilight" by Stephenie Meyer