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a substance obtained from nutgalls, oak bark, and other plant parts, formerly used in medicine as an astringent. It is no longer used alone because it can be absorbed through mucous membranes or damaged skin in amounts sufficient to produce hepatic necrosis, although it is still used as a component of dermatological preparations.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
Any one of a group of complex nonuniform plant constituents that can be classified into hydrolyzable tannins (esters of a sugar, usually glucose, and one or several trihydroxybenzenecarboxylic acids) and condensed tannins (derivatives of flavonols). Tannins are used in tanning, dyeing, photography, and as clarifying agents for beer and wine. Sometimes used synonymously with tannic acid. Tannins form black stains in the presence of iron.
Farlex Partner Medical Dictionary © Farlex 2012
Any of a family of compounds that react with proteins to produce a leathery coating on animal tissues and give woods their brown, red and yellow hues; tannins are anti-inflammatory, antimicrobial and astringent.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
A complex nonuniform plant constituent; used in tanning, dyeing, photography, and as clarifying agents for beer and wine.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
tannina complex organic compound occurring widely in plant sap, particularly in bark, leaves and unripe fruits, that is used in the production of leather and ink.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
Complex nonuniform plant constituent used in tanning, dyeing, photography, and as clarifying agents for beer and wine. Sometimes used synonymously with tannic acid.
Medical Dictionary for the Dental Professions © Farlex 2012