repurchase vs buy

repurchase and buy both are nouns.

Word	Noun	Adjective	Verb	Adverb
repurchase	Yes	No	Yes	No
buy	Yes	No	Yes	No

As verbs, buy is a hypernym of repurchase; that is, buy is a word with a broader meaning than repurchase:

Other hypernyms of repurchase include purchase.

repurchase (noun)	buy (noun)
the act of purchasing back something previously sold	an advantageous purchase

repurchase (verb)	buy (verb)
buy what had previously been sold, lost, or given away	accept as true
	obtain by purchase; acquire by means of a financial transaction
	make illegal payments to in exchange for favors or influence
	acquire by trade or sacrifice or exchange
	be worth or be capable of buying