The word acute describes something sharp, severe, or intense, often referring to something that demands immediate attention.

In medicine, an acute illness comes on suddenly and severely. An acute case of appendicitis requires emergency surgery, unlike a chronic condition that develops slowly over time. An acute allergic reaction happens fast and can be serious, while a mild allergy might just make your nose itch occasionally.

Acute can also describe mental sharpness. Someone with acute observational skills notices tiny details others miss, like a detective spotting a crucial clue at a crime scene. A friend with acute hearing might detect sounds you can't even notice.

The word also describes intense pain or problems. An acute shortage of water during a drought creates immediate danger. Acute embarrassment is that overwhelming flush of shame you feel after tripping in front of the whole cafeteria.

In geometry, an acute angle measures less than 90 degrees: it's sharp and pointed, like the tip of an arrow, rather than square like a corner of a book.

Whether describing a sudden illness, a sharp mind, or a pointed angle, acute always suggests something concentrated and intense rather than dull or gradual.