butter cookie vs cooky

butter cookie and cooky both are nouns.

Word	Noun	Adjective	Verb	Adverb
butter cookie	Yes	No	No	No
cooky	Yes	No	No	No

As nouns, cooky is a hypernym of butter cookie; that is, cooky is a word with a broader meaning than butter cookie:

Other hypernyms of butter cookie include biscuit, cookie.

butter cookie (noun)	cooky (noun)
cookie containing much butter	any of various small flat sweet cakes
	the cook on a ranch or at a camp