mordant

Any substance used to facilitate the fixing of a dye to a fibre; usually a metallic compound which reacts with the dye using chelation.

Any corrosive substance used in etching.

A glutinous size used as a ground for gilding, to make the gold leaf adhere.

To subject to the action of, or imbue with, a mordant.

“Mordant these goods for dyeing.”

Having or showing a sharp or critical quality

Serving to fix a dye to a fibre.