sufficient vs sufficiency

sufficient is not a noun while sufficiency is a noun.

Word	Noun	Adjective	Verb	Adverb
sufficient	No	Yes	No	No
sufficiency	Yes	No	No	No

sufficient (noun)	sufficiency (noun)
	the quality of being sufficient for the end in view
	an adequate quantity; a quantity that is large enough to achieve a purpose
	sufficient resources to provide comfort and meet obligations

sufficient (adjective)	sufficiency (adjective)
of a quantity that can fulfill a need or requirement but without being abundant