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

The apparent copy of Hipparchus’ catalog was written using ink made from tannin-rich oak galls, the common, often-round growths on oak trees triggered by larval wasps. —Ethan Baron, Mercury News, 24 Jan. 2026

Their Clau de Nell 2022 Cabernet Franc has aromas of ripe red plum, red raspberry, and black olive paste with flavors of red plum, roasted red peppers, and red currant sheathed in velvety tannins. —Mike Desimone, Robb Report, 22 Jan. 2026

Oregon Pinot Noir is often lighter in body, with higher acidity and finer tannins. —Emily Price, Forbes.com, 22 Jan. 2026

It can be eaten at any ripeness stage, thanks to its low levels of tannins. —Randi Gollin, Martha Stewart, 11 Jan. 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