definition of
mordant

[1] #1 mordant n. a substance used to treat leather or other materials before dyeing; aids in dyeing process. wn

[2] #2 mordant s. [black, grim] harshly ironic or sinister; "black humor"; "a grim joke"; "grim laughter"; "fun ranging from slapstick clowning ... to savage mordant wit". wn

[3] #3 mordant s. [caustic, corrosive, erosive, vitriolic] of a substance, especially a strong acid; capable of destroying or eating away by chemical action. wn