purchase vs pay

purchase and pay both are nouns.

Word	Noun	Adjective	Verb	Adverb
purchase	Yes	No	Yes	No
pay	Yes	No	Yes	No

purchase (noun)	pay (noun)
the acquisition of something for payment	something that remunerates
the mechanical advantage gained by being in a position to use a lever
a means of exerting influence or gaining advantage
something acquired by purchase

purchase (verb)	pay (verb)
obtain by purchase; acquire by means of a financial transaction	dedicate
	bear (a cost or penalty), in recompense for some action
	convey, as of a compliment, regards, attention, etc.; bestow
	give money, usually in exchange for goods or services
	bring in
	do or give something to somebody in return
	cancel or discharge a debt
	make a compensation for
	discharge or settle
	render
	be worth it