# toxic

/ˈtɑksɪk/ (US) · /tˈɒksɪk/ (UK)

Source: https://englishreference.com/word/toxic
Updated: 2026-06-19

## Senses

### 1. poisonous

adjective · CEFR B1

containing poison or being very harmful to your health if you touch or eat it.

For teachers: containing or being a poisonous substance that is harmful or lethal if ingested, inhaled, or absorbed.

- The factory was fined for dumping toxic waste into the local river.
- The cleanup crew wore protective suits to prevent any contact with the toxic chemicals leaking from the overturned tanker.

### 2. harmful relationships

adjective · CEFR B2

describing a person or situation that is very unpleasant and causes a lot of unhappiness.

For teachers: metaphorically describing a person, relationship, or workplace culture that is psychologically harmful or destructive.

- She decided to leave her job because the office environment had become toxic.
- Psychologists warn that staying in a toxic relationship can have long-term effects on a person's self-esteem and mental well-being.

### 3. grossly unwell

adjective · CEFR C1 · Technical

appearing very sick, especially when a person's whole body is struggling to work.

For teachers: appearing clinically unwell, often indicating a systemic infection or a life-threatening compromise of vital systems.

- The doctor noticed the patient looked toxic and ordered immediate blood tests.
- The infant appeared toxic upon admission, showing signs of respiratory distress and poor circulation that suggested a severe systemic infection.

## Examples

- The factory was fined for dumping toxic waste into the river.
- She decided to leave her job because the office culture had become toxic and stressful.
- Environmental scientists are monitoring the lake for toxic runoff that could devastate the local ecosystem and contaminate the town's primary water supply.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.