Adjective
1. extremely poisonous or injurious; producing venom;
"venomous snakes""a virulent insect bite"2. 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"3. marked by deep ill will; deliberately harmful;
"a malevolent lie""poisonous hate...in his eyes"- Ernest Hemingway"venomous criticism""vicious gossip"