catechu

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A spiny Asian tree (Acacia catechu) having bipinnately compound leaves, spikes of yellow flowers, and dark heartwood.
2. n. A raw material obtained from the heartwood of this plant, used in the preparation of tannins and brown dyes. Also called cutch.
3. n. See betel palm.

Century Dictionary and Cyclopedia

1. n. A name common to several astringent extracts prepared from the wood, bark, and fruit of various plants. The true catechu, or cutch, of commerce is a dark-brown, hard, and brittle substance, extracted by decoction and evaporation from the wood of Acacia Catechu and A. suma, East Indian trees. It is one of the best astringents to be found in the materia medica, and is largely used in tanning, calico-printing, etc. Pale or gambier catechu is obtained from a rubiaceous climber, Uncaria gambier (see gambier). A kind of catechu is also made from the nut of the betel-palm, Areca Catechu, but it is not an article of commerce. An artificial catechu, serviceable in dyeing, is obtainable from mahogany and similar woods. Also cashoo.
2. n. It is used extensively in cotton-dyeing, under the name of cutch, for the production of tan shades. It consists chiefly of two principles, catechu-tannic acid, and catechin or catechuic acid, which are accompanied by a brown amorphous substance called japonic acid. Japonic acid is the final oxidation-product of catechuic acid, and catechu-tannic acid is an intermediate oxidation-product. Bombay catechu, obtained from the heart-wood of the catechu palm. Areca Catechu, is considered the best quality for dyeing purposes; its principal constituent is catechu-tannic acid. Bengal catechu, obtained from the pods and twigs of the acacia, is less soluble than Bombay catechu. Cube catechu is the same as gambier catechu, which is a product of the leaves of Ouronparia Gambier and is sold in the form of yellow cubes.

Wiktionary

1. n. A gummy extract of any of several species of Acacia, produced by boiling the wood of the tree in water and evaporating the resulting liquid.

GNU Webster's 1913

1. n. (Chem.) A dry, brown, astringent extract, obtained by decoction and evaporation from the Acacia catechu, and several other plants growing in India. It contains a large portion of tannin or tannic acid, and is used in medicine and in the arts. It is also known by the names terra japonica, cutch, gambier, etc.

WordNet 3.0

1. n. East Indian spiny tree having twice-pinnate leaves and yellow flowers followed by flat pods; source of black catechu
2. n. extract of the heartwood of Acacia catechu used for dyeing and tanning and preserving fishnets and sails; formerly used medicinally