tannin vs tannic acid

tannin and tannic acid both are nouns.

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

As nouns, tannin and tannic acid are synonyms defined as:

tannin and tannic acid: any of various complex phenolic substances of plant origin; used in tanning and in medicine

tannin (noun)	tannic acid (noun)
any of various complex phenolic substances of plant origin; used in tanning and in medicine	any of various complex phenolic substances of plant origin; used in tanning and in medicine