obtuse

American  

[uhb-toos, -tyoos] / əbˈtus, -ˈtyus /

adjective

1. not quick or alert in perception, feeling, or intellect; not sensitive or observant; dull.

   Synonyms:

   dim, slow, boorish, gauche, unobservant, imperceptive, blind, insensitive, tactless, unfeeling

2. not sharp, acute, or pointed; blunt in form.

3. (of a leaf, petal, etc.) rounded at the extremity.

4. indistinctly felt or perceived, as pain or sound.

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obtuse British  

/ əbˈtjuːs /

adjective

1. mentally slow or emotionally insensitive

2. maths

   1. (of an angle) lying between 90° and 180°

   2. (of a triangle) having one interior angle greater than 90°

3. not sharp or pointed

4. indistinctly felt, heard, etc; dull

   obtuse pain

5. (of a leaf or similar flat part) having a rounded or blunt tip

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Other Word Forms

• obtusely
  adverb
• obtuseness
  noun
• subobtuse
  adjective
• subobtusely
  adverb

Etymology

Origin of obtuse

First recorded in 1500–10; from Latin obtūsus “dulled,” past participle of obtundere, equivalent to ob- ob- + tūd-, variant stem of tundere “to beat” + -tus past participle suffix, with dt > s

Explanation

The adjective obtuse is good for describing someone slow on the uptake: "Don't be so obtuse: get with the program!" The adjective obtuse literally means "rounded" or "blunt," but when it's used for a person, it means "not quick or alert in perception" — in other words, not the sharpest tool in the shed. It's not just for dull people, but also dull angles: in geometry, an obtuse angle is one that is not so sharp (between 90 and 180 degrees).

Example Sentences

To demand more seems to be willfully obtuse, more like a social media shame ritual than anything useful.

From The Wall Street Journal • Apr. 24, 2026

Nothing is promised, and Mazzulla remains comically obtuse about Tatum’s status, but NBC continued to tease the possibility Sunday with a behind-the-scenes documentary about his post-surgery recovery.

From The Wall Street Journal • Mar. 2, 2026

But Schaffer’s film has the uniquely difficult task of making Frank look like an idiot without making the police as a whole seem lovably obtuse.

From Salon • Aug. 1, 2025

"And while that sounds obtuse, golfers know what I mean. Trump was a golfing enthusiast long before he was president. And he will be long after, as well."

From BBC • Jul. 25, 2025

Perhaps this was the son of one of their friends—but this kind of subterfuge was pretty obtuse, even for them.

From "Scythe" by Neal Shusterman