noxious
[adjective]
Synonyms: harmful, deadly, destructive, foul, hurtful, injurious, poisonous, unhealthy, unwholesome

---

Antonyms: wholesome, sanitary, innocuous, innoxious
Related Words: fetid, noisome, putrid, stinking

---

English Thesaurus: poisonous, toxic, noxious, hazardous, deadly, ...

[TahlilGaran] English Synonym Dictionary ▲

nox‧ious /ˈnɒkʃəs $ ˈnɑːk-/ adjective formal
[Date: 1400-1500; Language: Latin; Origin: noxius, from noxa 'harm']
harmful or poisonous Synonym : toxic ⇒ innocuous:
noxious fumes

[TahlilGaran] Dictionary of Contemporary English ▲

poisonous containing or producing a substance that is likely to kill you, or make you very ill:
poisonous gas
poisonous snakes
The plant is poisonous to humans and animals.
toxic toxic chemicals and waste are poisonous to people and the environment:
Crops were sprayed with highly toxic chemicals.
Lead is toxic to humans.
The site was used for the disposal of toxic waste.
noxious [usually before noun] formal noxious substances and gases are poisonous:
Vehicles pollute the air with noxious fumes
The soil may be contaminated with noxious substances.
hazardous [usually before noun] hazardous substances are likely to harm people, animals, or the environment if they are not dealt with or got rid of carefully:
Lead is one of the most hazardous substances known, causing cancer and nerve damage.
The building is now unoccupied, and all radioactive or hazardous materials have been removed.
hazardous nuclear waste
deadly extremely poisonous and likely to kill you – used especially about poisons and snakes:
a deadly poison
a deadly snake
Terrorists plotted to release a deadly gas.

[TahlilGaran] English Thesaurus ▲