toxic

toxic — adjective

1. containing poison or harmful chemicals that can make people, animals, or plants

1.adjectiveB1
Definition

containing poison or harmful chemicals that can make people, animals, or plants ill or cause death if swallowed, breathed in, or touched.

Example

Factory workers must wear protective masks when handling toxic chemicals.

collocation: toxic chemicals / toxic fumes / toxic waste

The river became toxic after the factory dumped waste into it.

Common collocations
  • toxic chemicals
  • toxic waste
  • toxic fumes
  • toxic substance
Synonyms
  • poisonous

    more common in everyday contexts involving plants, food, and animals

  • noxious

    restricted to gases, fumes, and smells that harm health

  • deadly

    emphasises the fatal result rather than the chemical nature

Antonyms
  • non-toxic

    describes substances that are safe to handle or consume

  • harmless

    broader term for anything that causes no damage

Grammar Patterns

toxic + noun

be + toxic

Usage Note

Frequently used attributively before nouns describing harmful substances: toxic waste, toxic fumes, toxic chemicals.

Common Mistakes

This snake is toxic.
This snake is venomous.
'toxic' describes things that poison when eaten or absorbed; 'venomous' describes animals that inject poison through a bite or sting.

2. describes words, actions, or a person's character as extremely unkind, cruel, or

2.adjectiveB2
Definition

describes words, actions, or a person's character as extremely unkind, cruel, or deliberately hurtful to others.

Example

Harper's toxic remarks made everyone in the office feel anxious and worthless.

collocation: toxic remarks / toxic comments / toxic behaviour

The coach's toxic behaviour toward the younger players finally got him fired.

Common collocations
  • toxic remarks
  • toxic comments
  • toxic behaviour
  • toxic person
Synonyms
  • malicious

    more formal, emphasises deliberate intention to harm

  • poisonous

    informal synonym for a cruel or unpleasant person

  • nasty

    less intense, describes generally unpleasant rather than deeply harmful behaviour

Antonyms
  • kind

    describes warm, considerate behaviour

  • supportive

    specifically about offering help and encouragement

Grammar Patterns

toxic + noun (remarks, behaviour, person)

be + toxic

Usage Note

Commonly used in informal contexts about interpersonal behaviour. Subject is typically a person, their words (remarks, comments), or treatment of others.

Common Mistakes

He is a toxic person' (when you mean physically poisoned).
He is a toxic person' (meaning cruel or manipulative) is correct in modern usage
context determines whether you mean literal poison or cruel behaviour.

3. describes a relationship, workplace, or social setting where ongoing negative pa

3.adjectiveB2
Definition

describes a relationship, workplace, or social setting where ongoing negative patterns gradually damage a person's emotional well-being.

Example

Luca finally left the toxic environment of his old workplace last month.

collocation: toxic environment / toxic workplace / toxic relationship

Maja ended her two-year relationship with Dario when he saw how toxic it had become.

collocation: toxic relationship

Common collocations
  • toxic relationship
  • toxic environment
  • toxic workplace
  • toxic culture
Synonyms
  • unhealthy

    less intense, describes a negative dynamic without implying deliberate harm

  • destructive

    emphasises the damage being caused

  • abusive

    stronger, implies serious mistreatment rather than general negativity

Antonyms
  • healthy

    describes a positive, supportive environment

  • nurturing

    emphasises growth and care

Grammar Patterns

toxic + noun (relationship, environment, culture)

become + toxic

Usage Note

Distinguish from sense 2 (CRUEL BEHAVIOR): sense 2 targets a person's character or words; this sense targets the overall atmosphere or system (workplace, family, culture) rather than an individual's actions.

Common Mistakes

The office culture is very toxic person.
The office culture is very toxic.
'toxic' describes the culture itself; do not add 'person' when describing an environment.

4. describes loans, investments, or debts that have become so risky or worthless th

4.adjectiveC1
Definition

describes loans, investments, or debts that have become so risky or worthless that they cannot be easily sold or recovered.

Example

The bank lost billions on toxic mortgage loans during the financial crisis.

collocation: toxic debt / toxic assets / toxic loans

Constanza warned investors against buying toxic debt from struggling banks.

Common collocations
  • toxic assets
  • toxic debt
  • toxic loans
  • toxic mortgages
Synonyms
Antonyms
  • safe

    describes low-risk investments

  • liquid

    describes assets that can be easily sold

Grammar Patterns

toxic + noun (assets, debt, loans)

Usage Note

Restricted to financial contexts. Most commonly appears in the noun phrases 'toxic assets' and 'toxic debt.' Frequently used in past-tense reporting of financial crises.

Common Mistakes

My personal loan became toxic.
The bank's mortgage portfolio contained toxic assets.
'toxic' in finance applies to institutional debt and investments, not ordinary personal loans.

toxic — noun

toxic — combining form

Word family

  • toxicity
    nounB2
  • toxin
    nounB2
  • nontoxic
    adjectiveB2
  • toxicology
    nounC1
  • toxicologist
    nounC1
  • toxically
    adverbC1

Synonym discussion

Sense: adjective/1

Toxic, poisonous, venomous, and noxious all describe something that can harm living things, but their use differs in important ways. Poisonous is the everyday word for plants, food, chemicals, and animals that cause harm when eaten or touched — 'poisonous mushrooms' is far more natural than 'toxic mushrooms.' Venomous applies only to animals (snakes, spiders, scorpions) that inject venom through a bite or sting; a cobra is venomous, not poisonous. Noxious is restricted to gases, fumes, and odours that are harmful to breathe — 'noxious fumes' but not 'noxious berries.' Toxic is the broadest and most formal of the four: it covers literal poisons (toxic waste, toxic chemicals), metaphorical harm (toxic relationship, toxic culture), and financial risk (toxic assets). In scientific writing, prefer toxic for chemical or laboratory contexts. In everyday conversation, use poisonous for edible things and venomous for biting creatures.

toxic ↗poisonous ↗venomousnoxious

Common collocations

Nouns

  • levels of toxic
  • signs of toxic
  • exposure to toxic

Adverbs

  • highly toxic
  • extremely toxic
  • potentially toxic
  • acutely toxic

Phrases

  • toxic shock
  • toxic substance
  • toxic waste disposal

Prepositions

  • toxic to
  • toxic for

Etymology

GreekLatinFrenchEnglish

The word 'toxic' traces back to the ancient Greek word 'toxon,' meaning 'bow.' The Greeks used 'toxikon pharmakon' ('arrow poison') for the poison that warriors smeared on arrow tips. Latin borrowed this as 'toxicum' (poison), and Late Latin turned it into the adjective 'toxicus' (poisoned). French passed 'toxique' into English around the 1660s. For most of its history, 'toxic' referred only to literal poisons. The modern extension to describe cruel people (sense 2) and harmful environments (sense 3) emerged in the 1980s and surged in popular usage after the 2008 financial crisis, when 'toxic assets' (sense 4) became a household term.