quantity vs deficient

quantity is a noun but deficient is not a noun.

Word	Noun	Adjective	Verb	Adverb
quantity	Yes	No	No	No
deficient	No	Yes	No	No

quantity (noun)	deficient (noun)
how much there is or how many there are of something that you can quantify
an adequate or large amount
the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable

quantity (adjective)	deficient (adjective)
	of a quantity not able to fulfill a need or requirement
	inadequate in amount or degree
	falling short of some prescribed norm