inject vs practice of medicine

inject is not a noun while practice of medicine is a noun.

Word	Noun	Adjective	Verb	Adverb
inject	No	No	Yes	No
practice of medicine	Yes	No	No	No

inject (noun)	practice of medicine (noun)
	the learned profession that is mastered by graduate training in a medical school and that is devoted to preventing or alleviating or curing diseases and injuries

inject (verb)	practice of medicine (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