to strip a surface bare by rubbing or plucking, leaving it smooth, bald, or gleaming
One picture holds this word together: a surface stripped down until it is bare. Whatever covers a thing, hair on a head, tarnish on a bronze bowl, dullness on a blade, is rubbed or pulled away, and what remains is smooth, gleaming, or bald. The same verb that describes a grieving man tearing hair from his beard (Ezra 9:3) also describes a craftsman burnishing bronze until it shines (1 Kings 7:45).
Because the action stays the same while the object changes, English has to reach for several different words. When the surface is hair, the result is baldness, a head whose hair has fallen out, close to the ordinary word for going bald (קָרַח) and distinct from deliberately shaving it off (גָּלַח). When the surface is metal, the result is a polished, burnished shine; in Ezekiel's sword poem the blade is both whetted sharp (לָטַשׁ) and rubbed to a bright gleam, two steps in readying it for slaughter. When the surface is skin, the result is a body worn raw and bare (Ezekiel 29:18) or a people pictured as smooth and hairless (Isaiah 18:2).
The Aramaic form of the same verb (מְרַט) surfaces once, in Daniel's vision of a beast whose wings are plucked off, the identical idea of pulling a covering away to leave the thing bare.