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

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

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 realize that my humor on “Red Eye” was deliberately obtuse in some ways, and not really deliberately.

From Los Angeles Times • Sep. 3, 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

Mother noticed the rest of us sitting openmouthed and snapped, “You are so obtuse sometimes, Alfred. We’ll discuss it later.”

From "The Evolution of Calpurnia Tate" by Jacqueline Kelly