jejuneness vs dullness

jejuneness and dullness both are nouns.

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

As nouns, dullness is a hypernym of jejuneness; that is, dullness is a word with a broader meaning than jejuneness:

jejuneness (noun)	dullness (noun)
the quality of being vapid and unsophisticated	lack of sensibility
quality of inadequate nutritive value	without sharpness or clearness of edge or point
lacking and evidencing lack of experience of life	the quality of lacking interestingness
	a lack of visual brightness
	the quality of being slow to understand