tannic acid

noun Chemistry.
See under tannin.


Dictionary.com Unabridged


Chemistry. any of a group of astringent vegetable principles or compounds, chiefly complex glucosides of catechol and pyrogallol, as the reddish compound that gives the tanning properties to oak bark or the whitish compound that occurs in large quantities in nutgalls (common tannin, tannic acid)
any of these compounds occurring in wine and imparting an astringent taste, especially in red wine.

1795–1805; earlier tanin < F. See tan1, -in2

nontannin, noun
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To tannic acid
World English Dictionary
tannin (ˈtænɪn)
Also called: tannic acid any of a class of yellowish or brownish solid compounds found in many plants and used as tanning agents, mordants, medical astringents, etc. Tannins are derivatives of gallic acid with the approximate formula C76H52O46
[C19: from French tanin, from tan1]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

vegetable substance capable of converting animal hide to leather, 1802, from Fr. tannin (1798), from tan "crushed oak bark containing tannin" (see tan). Tannic acid first recorded 1836, from Fr. acide tannique, inroduced 1834 by Pelouze.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

tannic acid n.

  1. A white or yellowish astringent powder used as a denaturant and in tanning and textiles.

  2. A lustrous yellowish to light brown amorphous, powdered, flaked, or spongy mass derived from the bark and fruit of many plants and used as a mordant and to clarify wine and beer.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
tannic acid   (tān'ĭk)  Pronunciation Key 
A lustrous, yellow-brown, amorphous tannin, having the chemical composition C76H52O46. It is derived from the bark and fruit of many plants and used in photography, as a mordant, and as a clarifying agent for wine and beer.
tannin   (tān'ĭn)  Pronunciation Key 
Any of various compounds, including tannic acid, that occur naturally in the bark and fruit of various plants, especially the nutgalls, certain oaks, and sumac. Tannins are polyphenols, and form yellowish to light brown amorphous masses that can be powdery, flaky, or spongy. They are used in photography, dyeing, in tanning leather, in clarifying wine and beer, and as an astringent in medicine. Tannins are also an important ingredient in tea.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
Apparently, this was a filtering effect of the tannic acid in the fresh water above.
Applying tannic acid to a burn was a way to create a thickened, protective cover.
The color comes from tannic acid that is leached from fallen leaves and other organic matter.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature