check out vs purchase

check out is not a noun while purchase is a noun.

Word	Noun	Adjective	Verb	Adverb
check out	No	No	Yes	No
purchase	Yes	No	Yes	No

check out (noun)	purchase (noun)
	the acquisition of something for payment
	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

check out (verb)	purchase (verb)
examine so as to determine accuracy, quality, or condition	obtain by purchase; acquire by means of a financial transaction
announce one's departure from a hotel
try to learn someone's opinions and intentions
record, add up, and receive payment for items purchased
withdraw money by writing a check
trace
be verified or confirmed; pass inspection