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"
Virulent feelings or actions are extremely bitter and hostile. Now he faces virulent attacks from the Italian media = vicious + virulently viru·lent·ly The talk was virulently hostile to the leadership