English Reference
adjective

toxic

adj.
US /ˈtɑksɪk/ UK /tˈɒksɪk/ tox·ic

  1. 01 B1 Intermediate Science

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

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

    Simple

    The factory was fined for dumping toxic waste into the local river.

    In context

    The cleanup crew wore protective suits to prevent any contact with the toxic chemicals leaking from the overturned tanker.

    harmlessnon toxicsafe
  2. 02 B2 Upper Intermediate

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

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

    Simple

    She decided to leave her job because the office environment had become toxic.

    In context

    Psychologists warn that staying in a toxic relationship can have long-term effects on a person's self-esteem and mental well-being.

  3. 03 C1 Advanced Technical Medicine

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

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

    Simple

    The doctor noticed the patient looked toxic and ordered immediate blood tests.

    In context

    The infant appeared toxic upon admission, showing signs of respiratory distress and poor circulation that suggested a severe systemic infection.

    septiccritically ill

Usage toxic chemicals · toxic masculinity

A Shropshire vicar played a key role in a new two-part BBC documentary featuring Welsh Hollywood actor Michael Sheen's investigation into toxic waste dumps.

BBC News· 15 Aug 2026

We are left with the sense that competitive mountain climbing can be a toxic pursuit, especially when climbers try to attract sponsors by performing “extraordinary” feats, as Harila puts it.

The Guardian· 11 Aug 2026

Borrowed from French toxique, from Late Latin toxicus (“poisoned”), from Latin toxicum (“poison”), from Ancient Greek τοξικόν (toxikón) [φάρμακον (phármakon)] ("poison for use on arrows"), from τοξικός (toxikós, “pertaining to arrows or archery”), from τόξον (tóxon, “bow”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Ancient Greek τοξικόν
Level C1 · Advanced
Frequency Common
Updated