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 sunshine sparkles upon the ripples of the gently moving water, which is clear and colored like tea by natural plant tannins. —Amy Green, Miami Herald, 9 Jan. 2026

For pieces that have developed tannin and lime deposits, add white vinegar. —Michele Laufik, Martha Stewart, 7 Jan. 2026

Chocolate is a combination stain of fat/oil and vegetable tannins. —Mary Marlowe Leverette, Southern Living, 26 Dec. 2025

This fruit is high in digestive enzymes known as tannins that can slow down the digestion of starch, reducing the amount of carbohydrates your body absorbs from eating. —Cristina Mutchler, Verywell Health, 22 Dec. 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