Obtuse

1. (now chiefly botany, zoology) Blunt; not sharp, pointed, or acute in form.

• (botany, zoology) Blunt, or rounded at the extremity.
• (geometry, specifically, of an angle) Larger than one, and smaller than two right angles, or more than 90° and less than 180°.
• (geometry, by ellipsis) Obtuse-angled, having an obtuse angle.

2. Intellectually dull or dim-witted.
3. Of sound, etc.: deadened, muffled, muted.
4. Indirect or circuitous.

(intellectually dull): dense, dim, dim-witted, thick (informal)

(of a sound): deadened, muffled

(of a triangle): obtuse-angled

(now chiefly botany, zoology): blunt, dull

(intellectually dull): bright, intelligent, on the ball, quick off the mark, quick-witted, sharp, smart

(deadened, muffled, muted): clear, sharp

(of an angle): acute

(of a triangle): acute, acute-angled

(now chiefly botany, zoology): pointed, sharp