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

Ms. Field finds this obtuse, considering America’s actual history.

From The Wall Street Journal • Nov. 2, 2025

Though Godard later came to be synonymous with turgid, obtuse cinema, “Nouvelle Vague” is the opposite: a sprightly, effervescent ode to moviemaking as semi-controlled mischief.

From The Wall Street Journal • Oct. 30, 2025

"I think it would be a bit obtuse of me to speak about signings when clearly we have to improve and do better with what we have," he admitted.

From BBC • Aug. 22, 2025

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

I love the way you just made that completely obtuse.

From "Ask the Passengers" by A.S. King