injection vs inject

injection is a noun but inject is not a noun.

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

injection (noun)	inject (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)

injection (verb)	inject (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