inject vs injection

inject is not a noun while injection is a noun.

Word	Noun	Adjective	Verb	Adverb
inject	No	No	Yes	No
injection	Yes	No	No	No

inject (noun)	injection (noun)
	the forceful insertion of a substance under pressure
	the act of putting a liquid into the body by means of a syringe
	any solution that is injected (as into the skin)

inject (verb)	injection (verb)
give an injection to
to introduce (a new aspect or element)
to insert between other elements
feed intravenously
take by injection
force or drive (a fluid or gas) into by piercing