adj

acute

uh-KYOOT

adj

Sudden and severe, especially describing an illness or pain.

"He was admitted to hospital with acute appendicitis."

Very sharp, intense, or perceptive.

"She has an acute sense of hearing."

"His acute observation helped solve the mystery."

Geometry: describing an angle that measures less than 90 degrees.

"The triangle had one acute angle and two obtuse ones."

How to Use Acute

Learner’s notes

In plain EnglishSharp or intense — used for sudden severe illness, keen senses or perception, or narrow angles in geometry.

Common mistake

In medicine, "acute" means sudden-onset, not necessarily severe — it's the opposite of "chronic" (long-lasting), not of "mild."

Easily confused with

chronic →

Common pairings

acute pain acute angle acute sense

acuter comparative, more acute comparative, acuted past tense, acutes plural, acutes singular, acutest superlative, most acute superlative

Study it as flashcards or scroll it in Flow — saved to your collection.

Test yourself on “acute” A quick quiz — meaning, synonyms & usage →

Can you complete this real example?

He was admitted to hospital with _____ appendicitis.

From Latin acutus ("sharp, sharpened"), the past participle of acuere ("to sharpen"), from acus ("needle").

ute cute mute lute flute haute brute chute route minute refute astute