MORDANT is validvalid

to treat with a caustic substance [v MORDANTED, MORDANTING, MORDANTS] : MORDANTLY [adv]

45,585 of 196,601 in NWL2023·also valid in CSW24

biting [adj MORDANTLY] / to impregnate or treat with a substance that combines with and fixes a dyestuff [v -ED, -ING, -S]