mordant

Adjective

• of a substance, especially a strong acid; capable of destroying or eating away by chemical action

• harshly ironic or sinister
  • black humor
    
  • a grim joke
    
  • grim laughter
    
  • fun ranging from slapstick clowning ... to savage mordant wit
    

Noun

• a substance used to treat leather or other materials before dyeing; aids in dyeing process

Related words

• Synonyms: 
  caustic , corrosive , erosive , vitriolic , black , grim