madder

noun

• a Eurasian plant related to the bedstraws, with whorls of four to six leaves.

  • Genera Rubia and Sherardia, family Rubiaceae: in particular R. tinctorum, formerly cultivated for its root which yields a red dye
• [mass noun] a red dye or pigment obtained from the root of the madder, or a synthetic dye resembling it.