odiousness vs unpleasantness

odiousness and unpleasantness both are nouns.

Word	Noun	Adjective	Verb	Adverb
odiousness	Yes	No	No	No
unpleasantness	Yes	No	No	No

As nouns, unpleasantness is a hypernym of odiousness; that is, unpleasantness is a word with a broader meaning than odiousness:

odiousness (noun)	unpleasantness (noun)
the quality of being offensive	the quality of giving displeasure
	the feeling caused by disagreeable stimuli; one pole of a continuum of states of feeling