bluntness vs dullness

bluntness and dullness both are nouns.

Word	Noun	Adjective	Verb	Adverb
bluntness	Yes	No	No	No
dullness	Yes	No	No	No

As nouns, bluntness and dullness are synonyms defined as:

bluntness (noun)	dullness (noun)
without sharpness or clearness of edge or point	lack of sensibility
the quality of being direct and outspoken	without sharpness or clearness of edge or point
	the quality of lacking interestingness
	a lack of visual brightness
	the quality of being slow to understand