POISONOUS Synonyms: 48 Similar and Opposite Words

poisonous

adjective

ˈpȯiz-nəs

Definition of poisonous

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

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Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of poisonous Shrouded completely in a thick, poisonous cloud cover, its surface is obviously impossible to observe. — Mike Lynch, Twin Cities, 5 July 2026 All of this played out against an increasingly poisonous political environment. — Eric Berger, ArsTechnica, 3 July 2026 Sago palm, oleander, foxglove, azaleas and lily of the valley are all common and all poisonous. — Ryan Brennan, Miami Herald, 2 July 2026 Consuming this toxin can release poisonous hydrogen cyanide into the bloodstream. — Carrie Madormo, Verywell Health, 30 June 2026 See All Example Sentences for poisonous

Recent Examples of Synonyms for poisonous

Adjective

Power to the people is poison to the powerful.

— Sun Sentinel Editorial Board, Sun Sentinel, 10 Feb. 2026
Dropped in recent years because carbs are poison.

— Fort Worth Star-Telegram, Fort Worth Star-Telegram, 22 Jan. 2026

Definition of poison

Adjective

In addition to administering the toxic combination of medications, Hemphill failed to recognize and treat signs of respiratory distress, and administered the incorrect reversal medication for the kind of drug the girl had been given, Spragins wrote.

— Lillie Davidson, Fort Worth Star-Telegram, 16 July 2026
How many malodorously toxic episodes does that make toward the seven plagues in the Old Testament?

— Patt Morrison, Los Angeles Times, 15 July 2026

Definition of toxic

Adjective

European colonists in Australia encountered a suite of venomous snakes just as fearsome as those of the Libyan desert.

— Literary Hub, Literary Hub, 10 July 2026
While many of the snakes were said to be non‑venomous water snake and rat snakes, some were cobras, which are considered highly venomous, reported the Xiaoxiang Daily.

— Sylvie Zhuang, CNN Money, 7 July 2026

Definition of venomous

Browse Nearby Words

poisoning

poisonous

poisons

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“Poisonous.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/poisonous. Accessed 20 Jul. 2026.

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Synonyms of poisonous

adjective

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