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

Black walnut and a barely-there thread of dark cherry lend depth without bringing too much in the way of tannins. —David Thomas Tao, Forbes.com, 7 Aug. 2025

Why Tea Bags Work For Shoe Odor Tea bags have been known to be effective in combating mild odors in shoes due to their moisture-absorbing properties and the presence of tannins in tea, which have antibacterial effects. —Meghan Overdeep, Southern Living, 7 Aug. 2025

While the bigger California oaks produce acorns with high levels of tannins that could be toxic to people, the smaller Arizona species can be eaten raw. —Shaun McKinnon, AZCentral.com, 26 July 2025

Others avoid red wines to steer clear of hangover-inducing tannins. —Andrea Margolis, FOXNews.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