venomous

extremely poisonous or injurious; producing venom

• “venomous snakes”
• “a virulent insect bite”

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”

marked by deep ill will; deliberately harmful

• “a malevolent lie”
• “poisonous hate...in his eyes” Ernest Hemingway
• “venomous criticism”
• “vicious gossip”