tea biscuit vs teacake

tea biscuit and teacake both are nouns.

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

As nouns, tea biscuit and teacake are synonyms defined as:

tea biscuit and teacake: flat semisweet cookie or biscuit usually served with tea

tea biscuit (noun)	teacake (noun)
flat semisweet cookie or biscuit usually served with tea	any of various small cakes or cookies often served with tea
	flat semisweet cookie or biscuit usually served with tea