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.

extract of the heartwood of Acacia catechu used for dying and tanning and preserving fishnets and sails; formerly used medicinally

Catechu (also known as Cutch, or Cashoo) is an extract of any of several species of Acacia—but especially Acacia catechu—produced by boiling the wood in water and evaporating the resulting brew.

East Indian spiny tree having twice-pinnate leaves and yellow flowers followed by flat pods; source of black catechu

Katha Bark ground