tea biscuit vs cooky

tea biscuit and cooky both are nouns.

Word	Noun	Adjective	Verb	Adverb
tea biscuit	Yes	No	No	No
cooky	Yes	No	No	No

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

Other hypernyms of tea biscuit include biscuit, cookie.

tea biscuit (noun)	cooky (noun)
flat semisweet cookie or biscuit usually served with tea	any of various small flat sweet cakes
	the cook on a ranch or at a camp