poisonous

adjective

poi·​son·​ous ˈpȯiz-nəs 

ˈpȯi-zᵊn-əs

1

: destructive, harmful

2

a

: having the properties or effects of poison

poisonous gas

b

: producing a toxic substance that causes injury or death when absorbed or ingested

poisonous mushrooms

also : venomous

a poisonous spider

3

: spiteful, malicious

poisonously adverb

Synonyms

• envenomed
• poison
• poisoned
• toxic
• venomous

Examples of poisonous in a Sentence

Chocolate is poisonous to dogs.

This species of spider is extremely poisonous.

Recent Examples on the Web

Related article Elderly couple dies after eating poisonous pufferfish in Malaysia Chefs in Japan must train for at least two years before being allowed to take an examination to qualify to prepare fugu. —Chris Lau, CNN, 25 June 2024

Medicines gathered from toads can also be used, such as 5-MeO-DMT, which can also be derived from plants, and Kambo, a poisonous toad secretion that is applied to the skin through small burn wounds. —Food Drink Life, The Mercury News, 22 June 2024

There may be many of them, but cicadas are not dangerous, poisonous, or venomous.3 So, for now, their loud presence is not a cause for concern. —Beth Ann Mayer, Parents, 13 June 2024

In 1925: Allied powers in the League of Nations signed the Geneva Protocol, which reaffirmed prior bans on using poisonous gas in warfare and added the prohibition of bacteriological weapons. —Lorenzino Estrada, The Arizona Republic, 17 June 2024

Word History

First Known Use

15th century, in the meaning defined at sense 2

Kids Definition

poisonous

adjective

poi·​son·​ous ˈpȯiz-nəs 

-ᵊn-əs

: containing poison : having or causing an effect of poison

poisonously adverb

Medical Definition

poisonous

adjective

poi·​son·​ous ˈpȯiz-nəs, -ᵊn-əs 

1

: having the properties or effects of poison

poisonous gas

2

: producing a toxic substance that causes injury or death when absorbed or ingested

poisonous frogs and plants

also : venomous