Synonyms of poisonous

poisonous

adjective

ˈpȯiz-nəs 

as in poisoned

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 & Similar Words

• poisoned
• poison
• toxic
• venomous
• harmful
• infective
• infectious
• envenomed
• malignant
• injurious
• pathogenic
• pestilential
• virulent
• lethal
• deleterious
• baneful
• noxious
• contagious
• unhealthful
• hurtful
• fatal
• deadly
• unwholesome
• nocuous
• unhealthy
• pestilent
• calamitous
• murderous
• fell

Antonyms & Near Antonyms

• nontoxic
• beneficial
• helpful
• healthy
• healthful
• wholesome
• nonpoisonous
• harmless
• curative
• remedial
• salutary
• benign
• palliative
• salubrious
• innocuous
• nonvenomous
• inoffensive
• nonfatal
• nonlethal

Example Sentences

Recent Examples of poisonous

Authorities finally caught a break when the autopsy determined David’s likely cause of death was poisonous mushrooms found in his stomach. — Caroline Blair, PEOPLE, 25 July 2026

Lydia Kiesling’s Mobility attempts something at once more traditional and more ambitious, exploring how a young woman tries to disentangle herself from the oil industry’s poisonous tendrils. — Robert Rubsam, The Atlantic, 20 July 2026

How plants poisonous to dogs cause harm Not all toxic plants affect dogs the same way, but many share similar chemicals that attack the digestive system. — Ryan Brennan, Fort Worth Star-Telegram, 15 July 2026

The pattern looks like the skin of a poisonous frog poking its head out from under its hiding place. — Jasmine Washington, InStyle, 15 July 2026