What is the meaning of Mordant?

Having or showing a sharp or critical quality

Serving to fix a dye to a fibre.

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.

present participle of mordre

biting, sharp, acrid

mordant

corrosive

mordent (ornament consisting of a single alternation between a given pitch and the one immediately below it)

mordant

Source: wiktionary.org