WordWeb Online

1. Taking more than usual time to learn or understand; lacking intellectual acuity
   "he was either normally stupid or being deliberately obtuse";
   - dense, dim [informal], dull, dumb, slow
    
2. (of a leaf shape) rounded at the apex
    
3. Lacking in insight or discernment
   "too obtuse to grasp the implications of his behaviour";
   - purblind
    
4. Of an angle; between 90 and 180 degrees

Derived forms: obtuser, obtusest

See also: simple, stupid, undiscerning, unsubdivided

Antonym: acute

Encyclopedia: Obtuse