from
The Collaborative International Dictionary of English v.0.48
Madder \Mad"der\ (m[a^]d"d[~e]r), n. [OE. mader, AS. maedere;
akin to Icel. ma[eth]ra.] (Bot.)
A plant of the genus {Rubia} ({Rubia tinctorum}). The root is
much used in dyeing red, and formerly was used in medicine.
It is cultivated in France and Holland. See {Rubiaceous}.
[1913 Webster]
Note: Madder is sometimes used in forming pigments, as lakes,
etc., which receive their names from their colors, such
as {madder yellow}.
[1913 Webster]
{Field madder}, an annual European weed ({Sherardia
arvensis}) resembling madder.
{Indian madder}, the East Indian {Rubia cordifolia}, used in
the East for dyeing; -- called also {munjeet}.
{Wild madder}, {Rubia peregrina} of Europe; also the {Galium
Mollugo}, a kind of bedstraw.
[1913 Webster]