rancidness vs aroma

rancidness and aroma both are nouns.

Word	Noun	Adjective	Verb	Adverb
rancidness	Yes	No	No	No
aroma	Yes	No	No	No

As nouns, aroma is a hypernym of rancidness; that is, aroma is a word with a broader meaning than rancidness:

Other hypernyms of rancidness include odor, odour, olfactory property, scent, smell, taste property.

rancidness (noun)	aroma (noun)
the property of being rancid	any property detected by the olfactory system
	a distinctive odor that is pleasant