biting, cutting, caustic, or sarcastic, as speech, wit, etc.
causing corrosion
acting as a mordant
noun
a substance used in dyeing to fix the coloring matter, as a metallic compound that combines with the organic dye to form an insoluble colored compound, or lake, in the fiber of the fabric
an acid or other corrosive substance used in etching to bite lines, areas, etc. into the surface