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

Other foods contain tannins and, when consumed in large amounts, could reduce how much iron your body takes in. —Caitlin Pagán, Verywell Health, 23 Sep. 2025

The tannins in coffee are very good at penetrating porous ceramic (as well as our teeth) and leaving behind ugly brown stains. —Brandee Gruener, Southern Living, 20 Sep. 2025

Medium-bodied, with excellent ripeness, nicely balanced tannins and an round, clean finish. —Tom Hyland, Forbes.com, 16 Sep. 2025

Certain beverages like matcha lattes may have less tannins because they're diluted with milk or water, and ceremonial grade matcha may have fewer tannins than culinary grade. —Charlotte Phillipp, People.com, 22 Aug. 2025

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