slenderness vs deficiency

slenderness and deficiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
slenderness	Yes	No	No	No
deficiency	Yes	No	No	No

As nouns, deficiency is a hypernym of slenderness; that is, deficiency is a word with a broader meaning than slenderness:

Other hypernyms of slenderness include inadequacy, insufficiency.

slenderness (noun)	deficiency (noun)
the quality of being slight or inadequate	lack of an adequate quantity or number
the property of an attractively thin person	the state of needing something that is absent or unavailable
relatively small dimension through an object as opposed to its length or width