dumb vs obtuse

dumb and obtuse both are adjectives.

Word	Noun	Adjective	Verb	Adverb
dumb	No	Yes	No	No
obtuse	No	Yes	No	No

As adjectives, dumb and obtuse are synonyms defined as:

dumb and obtuse: slow to learn or understand; lacking intellectual acuity

Other synonyms of dumb include dense, dim, dull, slow.

dumb (adjective)	obtuse (adjective)
slow to learn or understand; lacking intellectual acuity	of an angle; between 90 and 180 degrees
unable to speak because of hereditary deafness	(of a leaf shape) rounded at the apex
temporarily incapable of speaking	slow to learn or understand; lacking intellectual acuity
lacking the power of human speech	lacking in insight or discernment