catechin vs tannic acid

catechin and tannic acid both are nouns.

Word	Noun	Adjective	Verb	Adverb
catechin	Yes	No	No	No
tannic acid	Yes	No	No	No

As nouns, tannic acid is a hypernym of catechin; that is, tannic acid is a word with a broader meaning than catechin:

catechin: a tannic acid that is extracted from black catechu as a white crystalline substance
tannic acid: any of various complex phenolic substances of plant origin; used in tanning and in medicine

Other hypernyms of catechin include tannin.

catechin (noun)	tannic acid (noun)
a tannic acid that is extracted from black catechu as a white crystalline substance	any of various complex phenolic substances of plant origin; used in tanning and in medicine