MORDANT

I. adjective Etymology: Middle French, present participle of mordre to bite, from Latin mordēre; perhaps akin to Sanskrit mṛdnāti he presses, rubs Date: 15th century biting and caustic in thought, manner, or style ; incisive , acting as a ~, burning , pungent , see: caustic ~ly adverb II. noun Date: 1791 a chemical that fixes a dye in or on a substance by combining with the dye to form an insoluble compound, a corroding substance used in etching, III. transitive verb Date: 1836 to treat with a ~