poisonous

[poi-zuh-nuhs] / ˈpɔɪ zə nəs /

ADJECTIVE

harmful

Synonyms

STRONGEST

dangerous deadly destructive fatal lethal noxious pernicious toxic venomous vicious virulent

WEAK

bad baleful baneful corrupt corruptive deleterious detrimental evil hurtful infective malicious malignant mephitic miasmatic morbid mortal nocuous noisome peccant pestiferous pestilential poison septic toxicant toxiferous viperous

Antonyms

STRONGEST

gentle good harmless healthful healthy helpful kind life-giving nice nonpoisonous wholesome

WEAK

benevolent non-toxic

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Three people were recently hospitalized after eating poisonous wild mushrooms foraged in California wine country amid an unprecedented outbreak of illness and deaths linked to the practice statewide, health officials in Napa County announced.

From Los Angeles Times • May 15, 2026

But there are dozens of other poisonous snake species for which India does not have targeted antivenom.

From BBC • Feb. 1, 2026

In this poisonous time, those who grin at the notion of playing a Traitor may think twice about the potential cost to their principles.

From Salon • Jan. 28, 2026

Hydrogen cyanide, which is highly poisonous, can freeze into crystals at low temperatures.

From Science Daily • Jan. 16, 2026

I think of the massive elephant-ear leaves and poisonous plants, and the tests I need to run.

From "The Last Cuentista" by Donna Barba Higuera

Vocabulary lists containing poisonous

Week 4 Vocabulary

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Harmful, List 2

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-ious, -eous, -ous

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