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

Very concentrated fruit, velvety tannins, and a long, exquisite finish. —Liz Thach, Forbes.com, 6 Aug. 2025

Coffee contains caffeine and tannins, which are types of polyphenols that combine with minerals such as calcium, magnesium, zinc, phosphorus, and iron, and prevent their absorption.2 There’s also some evidence that heavy coffee consumption may affect B vitamin levels. —Jillian Kubala, Health, 31 July 2025

While the tannins in matcha can block the absorption of some iron-rich foods, most people don't need to worry about it. —Caitlin Pagán, Verywell Health, 2 July 2025

The King of Umbria Red Wines Sagrantino di Montefalco DOCG is another wine for people who love elegant tannins and a richly fruity taste. —Elisabetta Tosi, Forbes.com, 24 July 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