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

Spanish bluebells contain saponins, which smell and taste like soap, as well as poisonous cardiac glycosides. — ABC News, 8 Sep. 2026

As Anna covers for Fyodor’s addiction and increasingly unstable professional behavior, her devotion starts to look poisonous for them both. — Alison Foreman, IndieWire, 5 Sep. 2026

Boron can be poisonous for infants and babies if taken in high doses. — Bestreviews, Mercury News, 2 Sep. 2026

Eucalyptus oil and fresh leaves are poisonous when ingested or inhaled. — Sarah Bence, Verywell Health, 25 Aug. 2026