catechu n 1: extract of the heartwood of Acacia catechu used for dyeing and tanning and preserving fishnets and sails; formerly used medicinally [syn: {black catechu}, {catechu}] 2: East Indian spiny tree having twice-pinnate leaves and yellow flowers followed by flat pods; source of black catechu [syn: {catechu}, {Jerusalem thorn}, {Acacia catechu}]
Catechu \Cat"e*chu\, n. [See {Cashoo}.] (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. --Ure. --Dunglison. [1913 Webster]