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

With this potential even more poisonous investments in the bloated and indebted Paramount behemoth, there’s even more reason to reject it. — Abigail Disney, New York Daily News, 28 Sep. 2026

This can come with high levels of metals such as nickel and vanadium, which can damage engines, and sulfur, which can be poisonous to people. — Adam Kovac, Scientific American, 24 Sep. 2026

The fourth, the Indian rhinoceros, is vulnerable, its habitat shrinking rapidly as fragmented and isolated population groups spread across a shattered landscape littered with invasive plant species poisonous to the animals. — Literary Hub, 22 Sep. 2026

All parts of poison hemlock are poisonous if ingested, and exposure can be fatal. — Sj McShane, Martha Stewart, 18 Sep. 2026