to make bald: to leave a head stripped of its hair, usually by shaving or tearing the hair out as a public sign of grief.
This word is about a head with its hair gone, and in nearly every case the baldness is on purpose. When someone died, or when a city fell, mourners shaved or tore out the hair of the head, so a bald scalp became one of the standard public signs of grief, alongside torn clothes, sackcloth, and cuts made on the skin. Several verses pair the verb with the noun for the bald patch itself (קָרְחָה), which is why older English Bibles say "make baldness" rather than simply "shave."
The same act turns up in two very different kinds of writing, and they pull against each other. Priests were forbidden to do it, in the same breath as a ban on shaving (גָּלַח) the edge of the beard and on cutting the skin. Yet Jeremiah, Ezekiel, and Micah describe head shaving as simply what mourners do, with no hint of blame. Most scholars read the ban as an attempt to stamp out a funeral custom Israel shared with its neighbours, one bound up with tending or appeasing the dead, while the prophets show what people went on doing anyway.
One use has nothing to do with grief at all. In Ezekiel 29:18 the army that besieged Tyre comes away with every head rubbed bald and every shoulder worn raw, the hair simply chafed off by helmets and by the loads the soldiers carried. So the word can describe hair worn away by hard use just as readily as hair taken off deliberately.