English word tannic comes from Gaulish tanno-, and later French tannique (Tannic.)

Detailed word origin of tannic

Dictionary entry	Language	Definition
tanno-	Gaulish (cel-gau)
tan	French (fra)	Pulped oak bark used in the tanning process (i.e. of tanning leather).
tannique	French (fra)	Tannic.
tannic	English (eng)	Pertaining to, containing, or obtained from tannin.

Words with the same origin as tannic