obtuse

now chiefly botanyzoologyBlunt; not sharp, pointed, or acute in form.

botanyzoologyBlunt, or rounded at the extremity.

geometryspecifically of an angleLarger than one, and smaller than two right angles, or more than 90° and less than 180°.

geometryby ellipsisObtuse-angled, having an obtuse angle.

Intellectually dull or dim-witted.

Of sound, etc.: deadened, muffled, muted.

Indirect or circuitous.

Of an angle; between 90 and 180 degrees

(of a leaf shape) rounded at the apex

Lacking in insight or discernment

“too obtuse to grasp the implications of his behavior”

“a purblind oligarchy that flatly refused to see that history was condemning it to the dustbin”

Slow to learn or understand; lacking intellectual acuity

“so dense he never understands anything I say to him”

“never met anyone quite so dim”

“although dull at classical learning, at mathematics he was uncommonly quick”

obsoleteTo dull or reduce an emotion or a physical state.