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

Consuming high amounts of tannins may lead to adverse health effects in humans and animals, such as severe liver and kidney damage. —Jenna Prestininzi, Freep.com, 9 Oct. 2025

Soaking steel-cut oats overnight can cut back on cooking time and reduce antinutrients found in oats, like phytates, tannins, and oxalates. —Jillian Kubala, Health, 6 Oct. 2025

Damian Espinase Nandorfy and his team found that tannins can temporarily block small water channels in your tongue and mouth. —Khloe Quill, FOXNews.com, 5 Oct. 2025

The Chardonnay’s thicker skins add body and weight, while the Cabernet’s higher tannin ratio helps with long-term ageability. —Mike Desimone, Robb Report, 28 Sep. 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