blunt vs benumb

blunt is an adjective but benumb is not an adjective.

Word	Noun	Adjective	Verb	Adverb
blunt	No	Yes	Yes	No
benumb	No	No	Yes	No

As verbs, blunt and benumb are synonyms defined as:

Other synonyms of blunt include dull, numb.

blunt (adjective)	benumb (adjective)
characterized by directness in manner or speech; without subtlety or evasion
used of a knife or other blade; not sharp
having a broad or rounded end
devoid of any qualifications or disguise or adornment

blunt (verb)	benumb (verb)
make less sharp	make numb or insensitive
make less intense
make less lively, intense, or vigorous; impair in vigor, force, activity, or sensation
make dull or blunt
make numb or insensitive