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

Because of the high tannin and acidity levels in coffee, coffee grounds are able to break down strong proteins, making for tender meats. —Claire Hoppe Norgaard, Better Homes & Gardens, 26 Mar. 2025

Bogs are low-oxygen environments and prevent decay, and chemicals like tannins — used in tanning leather — preserve even the organic tissues from human remains, according to Britannica. —Irene Wright, Miami Herald, 21 Feb. 2025

This wine features wild strawberry, cherry, and earthy notes, with soft tannins and a balanced finish. —Joseph V Micallef, Forbes, 11 Mar. 2025

Best says the murky water can be full of tannins and algae and, once he’s started reaching for balls on the bottom, the disturbed silt reduces visibility dramatically. —Don Riddell, CNN, 10 Mar. 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