Obtuse means slow or unwilling to understand, dull or indistinct, blunt, or, of an angle, wider than 90° and narrower than 180°. A.Word.A.Day’s note on the obtuse barracuda, Sphyraena obtusata: the fish is not known to be slow, and its snout is pointed. What anatomists call obtuse is the rounded rear tip of its gill cover.