7 letters · 10 points in Scrabble
noun a substance used to treat leather or other materials before dyeing; aids in dyeing process
adjective harshly ironic or sinister
adjective of a substance, especially a strong acid; capable of destroying or eating away by chemical action
originFrom French mordant, from Latin mordeō. Doublet of mordent.
Etymology from Wiktionary, CC BY-SA 3.0