buy vs check out

buy is a noun but check out is not a noun.

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

buy (noun)	check out (noun)
an advantageous purchase

buy (verb)	check out (verb)
accept as true	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
make illegal payments to in exchange for favors or influence	try to learn someone's opinions and intentions
acquire by trade or sacrifice or exchange	record, add up, and receive payment for items purchased
be worth or be capable of buying	withdraw money by writing a check
	trace
	be verified or confirmed; pass inspection