'balau' originates from Malay/Indonesian, specifically the word 'balau', where it referred to certain Shorea trees and the timber they produce.

'balau' entered English through trade during the late 19th to early 20th century from Malay/Indonesian 'balau' and retained its original form and meaning as a timber name.

Initially it referred to the tree species ('a type of Shorea'), and over time its use in English came to denote the wood/timber produced by those trees.