insufficiency vs deficiency

insufficiency and deficiency both are nouns.

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

As nouns, insufficiency and deficiency are synonyms defined as:

Other synonyms of insufficiency include inadequacy.

insufficiency (noun)	deficiency (noun)
lack of an adequate quantity or number	lack of an adequate quantity or number
(pathology) inability of a bodily part or organ to function normally	the state of needing something that is absent or unavailable
a lack of competence