obtuse

adj. 1 dull-witted. 2 (of an angle) between 90 and 180. 3 of blunt form; not sharp-pointed or sharp-edged.  obtuseness n. [latin obtundo obtus- beat against, blunt]

superl. Not pointed or acute; blunt; -- applied esp. to angles greater than a right angle, or containing more than ninety degrees.