surgical operation vs hypophysectomise

surgical operation is a noun but hypophysectomise is not a noun.

Word	Noun	Adjective	Verb	Adverb
surgical operation	Yes	No	No	No
hypophysectomise	No	No	Yes	No

surgical operation (noun)	hypophysectomise (noun)
a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body

surgical operation (verb)	hypophysectomise (verb)
	remove the pituitary glands