operate vs practice of medicine

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

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

operate (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

operate (verb)	practice of medicine (verb)
perform surgery on
perform a movement in military or naval tactics in order to secure an advantage in attack or defense
handle and cause to function
keep engaged
perform as expected when applied
direct or control; projects, businesses, etc.