caustic
     adj 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" [syn: {acerb},
             {acerbic}, {acid}, {acrid}, {bitter}, {blistering}, {sulfurous},
             {sulphurous}, {venomous}, {virulent}, {vitriolic}]
     2: of a substance, especially a strong acid; capable of
        destroying or eating away by chemical action [syn: {corrosive},
         {erosive}, {vitriolic}]
     n : any chemical substance that burns or destroys living tissue
Source: WordNet® 2.0