scantiness vs deficiency

scantiness and deficiency both are nouns.

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

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

Other hypernyms of scantiness include inadequacy, insufficiency.

scantiness (noun)	deficiency (noun)
the quality of being meager	lack of an adequate quantity or number
Of a garment, the property of being very small, light, or revealing.	the state of needing something that is absent or unavailable