virulent

(s) extremely poisonous or injurious; producing venom
- venomous snakes
- a virulent insect bite
venomous, deadly,
(a) infectious; having the ability to cause disease
(s) 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
acid, blistering, caustic, vitriolic, acerb, acerbic, acrid, sulfurous, sulphurous, bitter,

venomous deadly acid blistering caustic vitriolic acerb acerbic acrid sulfurous sulphurous bitter

avirulent

virulently