A bath of dilute sulphuric or nitric acid, etc., to remove burnt sand, scale, rust, etc., from the surface of castings, or other articles of metal, or to brighten them or improve their colour.
A small or indefinite quantity or amount (of something); a little, a bit, a few. Usually in partitive construction, frequently without "of"; a single grain or kernel of wheat, barley, oats, sand or dust.