tannin

noun

tan·​nin ˈta-nən 

1

: any of various soluble astringent complex phenolic substances of plant origin used especially in tanning leather and dyeing textiles, manufacturing ink, clarifying wine and beer, and in medicine

2

: a substance that has a tanning effect

Examples of tannin in a Sentence

Recent Examples on the Web

Both Montecillo and Monte Rosso are aged for one year in 40 percent new French oak barrels and a second year in a 2,000-liter foudre, but Soto extracts earlier in fermentation for the Montecillo and then becomes gentler through the process to keep the tannins soft. —Mike Desimone, Robb Report, 15 Mar. 2026

Investigations for mycotoxins, heavy metals, pesticides and tannins have been fruitless. —The Washington Post, San Diego Union-Tribune, 14 Mar. 2026

Tea leaves contain tannins, complex chemical substances that give tea its astringency and dark color.1 Tannins are naturally absorbent and can help absorb odorous bacteria and moisture. —Asia London Palomba, The Spruce, 6 Mar. 2026

The leaves and other debris leach out their tannins to give the water its color. —Quiton White, Florida Times-Union, 3 Mar. 2026

Word History

Etymology

French, from tanner to tan

First Known Use

1802, in the meaning defined at sense 1

Rhymes for tannin

• canon
• fanon
• mannan
• olecranon
• trianon

Kids Definition

tannin

noun

tan·​nin ˈtan-ən 

: any of various substances from plants (as the oak or sumac) used in tanning leather, dyeing fabric and yarn, the making of ink, and in medicine

Medical Definition

tannin

noun

tan·​nin ˈtan-ən 

1

: any of various soluble astringent complex phenolic substances of plant origin used in tanning, dyeing, the making of ink, and in medicine as astringents and formerly in the treatment of burns

2

: a substance that has a tanning effect