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

Derived Forms

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

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

Brown’s lawyers, in their bail request, said he has health issues—including a heart aneurysm, as well as poor eyesight and hearing—that meant “he cannot get behind the steering wheel of a plane ever again.”

From The Wall Street Journal • May 24, 2026

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

After an aneurysm, your former life, free from the threat of death, of brain damage, of another aneurysm, is gone and buried.

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

I said that it was probably an aneurysm.

From "The Curious Incident of the Dog in the Night-Time" by Mark Haddon