Mordant

 
Adjective.

1: biting and caustic in thought, manner, or style: incisive.

2: acting as a mordant.

3: burning, pungent.

-mordantly, adverb.

[Origin: Middle French, present participle of mordre to bite, from Latin mordēre; perhaps akin to Sanskrit m dnāti he presses, rubs.]

(15th Century)

Mordant, noun:

1: a chemical that fixes a dye in or on a substance by combining with the dye to form an insoluble compound.

2: a corroding substance used in etching.

(1791)

Mordant, transitive verb: to treat with a mordant.

(1836)

“Neither of us was pleased to leave Bancroft behind. There was always a chance that he might decide he’d recovered sufficiently to be interviewed while our backs were turned. Maitland, of course, didn’t have an evening with Maeve as consolation, and he was mordant company all the way back to the nick.” – The Reckoning, Jane Casey.