poisonous
5 synonyms and 0 antonyms for poisonous, grouped by meaning and by how common each one is.
Adj — Containing enough poison to harm or kill if touched, eaten, or breathed in.
Synonyms
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
How to use poisonous
The word patterns that sound natural to a native speaker.
Etymology
From poison + the adjective suffix -ous.
Full origin of poisonous →Frequently asked questions
What does “poisonous” mean?
The word “poisonous” means containing enough poison to harm or kill if touched, eaten, or breathed in. In plain terms, capable of causing serious harm — either physically toxic, or (figuratively) toxic to a relationship or environment.
How do you pronounce “poisonous”?
“Poisonous” is pronounced POY-zuh-nuhs (/ˈpɔɪzənəs/ in IPA).
How do you use “poisonous” in a sentence?
Here is “poisonous” used in a sentence: “Some poisonous berries look almost identical to edible ones.”
What part of speech is “poisonous”?
“Poisonous” is an adjective.
Is “poisonous” a common word?
“Poisonous” is an uncommon word in modern English, usually learned at around the B1 level.
How many meanings does “poisonous” have?
“Poisonous” has 2 distinct senses listed in this dictionary. The most common is: containing enough poison to harm or kill if touched, eaten, or breathed in.
What is the difference between poisonous and venomous?
Poisonous describes something harmful if touched, eaten, or breathed in, while venomous specifically describes an animal that injects toxins through a bite or sting. A snake that bites and injects toxin is venomous, but a plant that is harmful to eat is poisonous, not venomous.
What is the difference between poisonous and toxic?
The two words overlap closely, but poisonous is most often used for substances or organisms capable of causing harm or death if ingested, touched, or inhaled, while toxic is a broader term that can also describe harmful environments, chemicals, or behavior. In practice, people frequently use them interchangeably.
Can "poisonous" describe something other than a physical substance?
Yes, poisonous is often used figuratively to describe something deeply harmful to a person's attitude or a relationship, such as a poisonous rumor or a poisonous work environment. This figurative use is very common alongside the literal, physical sense.