Probably a corruption of the Malay kacu.
catechu (countable and uncountable, plural catechus)
- A gummy extract of any of several species of Acacieae, produced by boiling the wood of the tree in water and evaporating the resulting liquid.
1837, Jonathan Pereira, “Lectures on Materia Medica: Lecture LXI”, in London Medical Gazette, volume XX, page 107:
- The pale catechus are usually sweeter and more pleasant for chewing.