rankness vs fruitfulness

rankness and fruitfulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
rankness	Yes	No	No	No
fruitfulness	Yes	No	No	No

As nouns, fruitfulness is a hypernym of rankness; that is, fruitfulness is a word with a broader meaning than rankness:

rankness: the property of producing abundantly and sustaining vigorous and luxuriant growth
fruitfulness: the quality of something that causes or assists healthy growth

Other hypernyms of rankness include fecundity.

rankness (noun)	fruitfulness (noun)
the attribute of having a strong offensive smell	the quality of something that causes or assists healthy growth
the property of producing abundantly and sustaining vigorous and luxuriant growth	the intellectual productivity of a creative imagination