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 concern about matcha and iron has to do with one of the compounds found in the powder: tannins. —Sarah Garone, Health, 1 May 2025

Medium-full, this offers excellent varietal purity, medium weight tannins, very good acidity and subtle wood notes. —Tom Hyland, Forbes.com, 1 May 2025

Meanwhile, exposure to oxygen encourages tannins in red wines to bind together, a process known as polymerization. —Mike Desimone and Jeff Jenssen, Robb Report, 27 Apr. 2025

Due to its high tannin content, wheatgrass juice is a natural diuretic that may help pass a kidney stone by increasing urine output.9 Lab studies published in 2020 suggest that wheatgrass extract may help dissolve and break up calcium stones. —Robert Burakoff, Verywell Health, 7 Apr. 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