fortis vs obtuse

fortis

• Strongly articulated (of a consonant), hence voiceless. 

• A fortis consonant. 

obtuse

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

• Blunt; not sharp, pointed, or acute in form. 

• Intellectually dull or dim-witted. 

• Obtuse-angled, having an obtuse angle. 

• Blunt, or rounded at the extremity. 

• Indirect or circuitous. 

• Larger than one, and smaller than two right angles, or more than 90° and less than 180°.