poison

1 of 3

noun

poi·​son ˈpȯi-zᵊn 

1

a

: a substance that through its chemical action usually kills, injures, or impairs an organism

b(1)

: something destructive or harmful

(2)

: an object of aversion or abhorrence

2

: a substance that inhibits the activity of another substance or the course of a reaction or process

a catalyst poison

poison

2 of 3

verb

poisoned; poisoning ˈpȯiz-niŋ 

ˈpȯi-zᵊn-iŋ

transitive verb

1

a

: to injure or kill with poison

b

: to treat, taint, or impregnate with or as if with poison

2

: to exert a baneful influence on : corrupt

poisoned their minds

3

: to inhibit the activity, course, or occurrence of

on the night when he poisoned my rest

—Charles Dickens

poisoner

ˈpȯiz-nər 

ˈpȯi-zᵊn-ər

noun

poison

3 of 3

adjective

1

: poisonous, venomous

a poison plant

a poison tongue

2

: impregnated with poison : poisoned

a poison arrow

Synonyms

Noun

• toxic
• disease
• venom
• toxin
• pesticide

Verb

• taint
• spoil
• stain
• mar
• darken

Adjective

• poisoned
• poisonous
• toxic

Examples of poison in a Sentence

Noun

a jar of rat poison

The killer gave her victims food laced with poison.

suck poison from a snake bite

The villain in the play dies by drinking a vial of poison.

Poverty is a poison to society.

Verb

How did the murderer poison the victim?

Hundreds were poisoned from drinking the contaminated water.

He was poisoned with cyanide.

The factory poisoned the air with its fumes.

Illegal dumping of waste is poisoning the stream and killing fish.

He poisoned their minds with hatred for her.

His angry outburst poisoned the atmosphere of the party.

Adjective

the witch gave Snow White a poison apple

Recent Examples on the Web

Noun

For example, researchers showcased that an AI system for detecting and protecting us from toxic poisons could easily be adjusted to craft new toxic mixtures that can wipe us out (see my coverage at the link here). —Lance Eliot, Forbes.com, 30 July 2025

On Tuesday, defense attorney Ashley Whitham didn't dispute that Angela had poison in her system, or that James was having an affair. —Rachel Treisman, NPR, 16 July 2025

Verb

But Trump has poisoned those relationships through his intemperate demands and threats. —Steve Chapman, Chicago Tribune, 6 Aug. 2025

Given the scale of the U.S.'s deficits, the patient may already be poisoned. —Clem Chambers, Forbes.com, 4 Aug. 2025

Adjective

Behavior and reproduction Most frogs are nocturnal, but not poison frogs. —National Geographic, 28 Feb. 2020

Some farmers even intentionally poison cranes to stop them from foraging in their crops. —National Geographic, 10 Feb. 2020

Word History

Etymology

Noun

Middle English, from Anglo-French poisun drink, potion, poison, from Latin potion-, potio drink — more at potion

First Known Use

Noun

13th century, in the meaning defined at sense 1a

Verb

14th century, in the meaning defined at sense 1a

Adjective

15th century, in the meaning defined at sense 1

Phrases Containing poison

• pick/choose your poison
• poison dart frog
• poison gas
• poison hemlock
• poison ivy
• poison oak
• poison-pen
• poison-pen letter
• poison pill
• poison sumac
• what's your poison?

Kids Definition

poison

1 of 3 noun

poi·​son ˈpȯiz-ən 

1

: a substance that by its chemical action can kill or injure a living thing

2

: something destructive or harmful

poison

2 of 3 verb

poisoned; poisoning ˈpȯiz-niŋ 

-ᵊn-iŋ

1

a

: to injure or kill with poison

b

: to put poison in or on

poisoned the air with its fumes

2

: to exert a harmful influence on : corrupt

poisoned their minds

poisoner

ˈpȯiz-nər 

-ᵊn-ər

noun

poison

3 of 3 adjective

: poisonous

a poison plant

Etymology

Noun

Middle English poison "poison, a poisonous drink," from early French poison "drink, potion, poison," from Latin potion-, potio "a drink, potion" — related to potion

Medical Definition

poison

1 of 3 noun

poi·​son ˈpȯiz-ᵊn 

1

: a substance that through its chemical action usually kills, injures, or impairs an organism

2

: a substance that inhibits the activity of another substance or the course of a reaction or process

a catalyst poison

poison

2 of 3 transitive verb

poisoned; poisoning ˈpȯiz-niŋ, -ᵊn-iŋ 

1

: to injure or kill with poison

2

: to treat, taint, or impregnate with poison

poison

3 of 3 adjective

1

: poisonous

a poison plant

2

: impregnated with poison

a poison arrow