Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary




Synonyms and Antonyms of poisonous

  1. containing or contaminated with a substance capable of injuring or killing a living thing <some evil person was leaving out poisonous meat for neighborhood dogs to eat> Synonyms envenomed, poison, poisoned, toxic, venomous Related Words contagious, infectious, infective, pathogenic, pestilent, pestilential; baneful, deleterious, harmful, hurtful, injurious, malignant, nocuous, noxious, virulent; unhealthful, unhealthy, unwholesome; calamitous, deadly, fatal, fell, lethal, murderous Near Antonyms beneficial, curative, healthful, healthy, helpful, palliative, remedial, salubrious, salutary, wholesome; benign, harmless, innocuous, inoffensive; nonfatal, nonlethal Antonyms nonpoisonous, nontoxic, nonvenomous

Learn More about poisonous

Seen and Heard

What made you want to look up poisonous? Please tell us where you read or heard it (including the quote, if possible).