tan·nic acid /ˌtænɪk-/ 名詞
Tan·nic a. Of or pertaining to tan; derived from, or resembling, tan; as, tannic acid.
Tannic acid. Chem. (a) An acid obtained from nutgalls as a yellow amorphous substance, C14H10O9, having an astringent taste, and forming with ferric salts a bluish-black compound, which is the basis of common ink. Called also tannin, and gallotannic acid. (b) By extension, any one of a series of astringent substances resembling tannin proper, widely diffused through the vegetable kingdom, as in oak bark, willow, catechu, tea, coffee, etc.
Tan·nin n. Chem. Same as Tannic acid, under Tannic.
Gal·lo·tan·nic a. Chem. Pertaining to the tannin or nutgalls.
Gallotannic acid. See Tannic acid, under Tannic.
n : any of various complex phenolic substances of plant origin;
used in tanning and in medicine [syn: tannin]