madder

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madder

1. any of several rubiaceous plants of the genus Rubia, esp the Eurasian R. tinctoria, which has small yellow flowers and a red fleshy root
2. the root of this plant
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

madder

[′mad·ər]
(materials)
The root of the madder plant (Rubia tinctorium), pulverized and used as source of glucosides to produce alizarin by fermentation. Also known as gamene.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.