leanness vs inadequacy

leanness and inadequacy both are nouns.

Word	Noun	Adjective	Verb	Adverb
leanness	Yes	No	No	No
inadequacy	Yes	No	No	No

As nouns, inadequacy is a hypernym of leanness; that is, inadequacy is a word with a broader meaning than leanness:

Other hypernyms of leanness include deficiency, insufficiency.

leanness (noun)	inadequacy (noun)
the property of having little body fat	unsatisfactoriness by virtue of being inadequate
the quality of being meager	lack of an adequate quantity or number
	a lack of competence