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

Prospect Lake Clean Water Center uses advanced nanofiltration and ion-exchange technologies that can strip out tannins that gave the water from Fiveash its yellow tint. — Susannah Bryan, Sun Sentinel, 30 Oct. 2026

Akin to coffee, tea, berries, and red wine, soy sauce is a tannin stain. — Jolie Kerr, Better Homes & Gardens, 29 Oct. 2026

Ungrafted vines give this vertical, saline energy, and the tannins are fine-grained. — Rachel Cormack, Robb Report, 23 Oct. 2026

This happens because the leaves contain tannins, the same compounds that turn your cup of tea a deep brown. — Brandee Gruener, Southern Living, 23 Oct. 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