poison

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

poisoned the knife

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

Synonyms of poison

• taint
• spoil
• stain
• mar
• darken

Examples of poison in a Sentence

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.

Recent Examples on the Web

LLMs can be poisoned and forced to hallucinate, or they can also be jailbroken and used for nefarious purposes. —Tom Kellermann, Forbes.com, 28 May 2026

Just months after Netflix announced its plans to produce the series, Lin was poisoned and killed at age 39. —Sylvie Zhuang, CNN Money, 28 May 2026

Xu, the former head of a subsidiary of Yoozoo Games, poisoned Lin in 2020 over being sidelined by the founder shortly after Xu helped his superior land the Netflix deal. —CBS News, 27 May 2026

Xu, the former head of a subsidiary of Yoozoo Games, poisoned Lin in December 2020 over being sidelined by the founder shortly after Xu helped his superior land the Netflix deal, local media reported. —ABC News, 26 May 2026

Word History

First Known Use

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

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

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