mordant

adjective

• (especially of humour) having or showing a sharp or critical quality; biting:a mordant sense of humour

noun

• 1a substance, typically an inorganic oxide, that combines with a dye or stain and thereby fixes it in a material.
• an adhesive compound for fixing gold leaf.

• 2a corrosive liquid used to etch the lines on a printing plate.

verb

• impregnate or treat (a fabric) with a mordant: mordanting a fibre is simple (as adjective mordanted)mordanted wool