Noun

• S: (n) mordant (a substance used to treat leather or other materials before dyeing; aids in dyeing process)

Adjective

• S: (adj) black, grim, mordant (harshly ironic or sinister) "black humor"; "a grim joke"; "grim laughter"; "fun ranging from slapstick clowning ... to savage mordant wit"
• S: (adj) caustic, corrosive, erosive, vitriolic, mordant (of a substance, especially a strong acid; capable of destroying or eating away by chemical action)