caustic in WordNet English dictionary

1. harsh or corrosive in tone
   "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "caustic jokes about political assassination, talk-show hosts and medical ethics"; "a sulfurous denunciation"; "a vitriolic critique"
   acerb  acerbic  acid  acrid  bitter  blistering  caustic  sulfurous  sulphurous  virulent  vitriolic 
   
2. of a substance, especially a strong acid; capable of destroying or eating away by chemical action
   caustic  corrosive  erosive  vitriolic  mordant 
   

1. any chemical substance that burns or destroys living tissue
   caustic