virulent

Synonyms: baneful deadly destructive fatal harmful infective injurious malign malignant mephitic pernicious poison septic toxic toxicant unhealthy unwholesome venomous

Antonyms: harmless healthy nonpoisonous

Synonyms: acrimonious antagonistic bitter cutting hateful malevolent malicious rancorous resentful scathing sharp spiteful splenetic stabbing unfriendly venomous vicious vindictive vitriolic

Antonyms: gentle kind nice