hazardous
[adjective]
Synonyms: dangerous, dicey (informal, chiefly Brit.), difficult, insecure, perilous, precarious, risky, unsafe

---

Antonyms: safe, unhazardous

---

English Thesaurus: dangerous, risky, hazardous, unsafe, treacherous, ...

[TahlilGaran] English Synonym Dictionary ▲

haz‧ard‧ous /ˈhæzədəs $ -zər-/ adjective
dangerous, especially to people’s health or safety
hazardous to
The chemicals in paint can be hazardous to health.
the disposal of hazardous waste

[TahlilGaran] Dictionary of Contemporary English ▲

hazardous
adj.
VERBS be, prove | become | consider sth
ADV. extremely, highly, particularly, very | rather, somewhat | potentially burning potentially hazardous medical waste
environmentally environmentally hazardous substances
PREP. for These conditions are very hazardous for shipping.
to chemicals that are hazardous to human beings

[TahlilGaran] Collocations Dictionary ▲

dangerous likely to cause death or serious harm, or cause something bad to happen:
Snow and ice are making driving conditions very dangerous.
dangerous drugs
a dangerous criminal
risky if something is risky, something bad could easily happen or you could easily make a mistake:
Doctors said it was too risky to operate.
a risky situation
hazardous /ˈhæzədəs $ -zər-/ especially written dangerous – used especially about substances, jobs, and journeys:
hazardous waste
hazardous chemicals
hazardous occupations
The expedition was extremely hazardous.
unsafe dangerous because someone is very likely to be hurt – used especially about places or conditions:
The roads are unsafe for cyclists.
unsafe working conditions
treacherous /ˈtretʃərəs/ formal literary places or conditions that are treacherous are very dangerous for anyone who is walking, driving, climbing etc in them:
The snow turned to ice, making conditions treacherous for walkers.
the island’s treacherous coastline
With no lighting, the roads can be treacherous.
perilous /ˈperələs, ˈperɪləs/ literary a perilous journey, situation etc is very dangerous:
a perilous journey across the sea
high-risk [only before noun] a high-risk job, situation, or behaviour is likely to be dangerous:
Drug users need to know that sharing needles is high-risk behaviour.

[TahlilGaran] English Thesaurus ▲

harmful causing physical harm – used especially about things that cause harm to your health, the environment etc:
Smoking is harmful to your health.
drugs with harmful side-effects
be bad for somebody/something to have a harmful effect on someone or something. This phrase is very commonly used in everyday English when saying that something is harmful:
Everyone knows that too much alcohol is bad for you.
damaging used about things that cause permanent physical harm, or that have a bad effect in other ways, for example on people’s opinion of someone:
Acid rain has a damaging effect on trees and the soil.
The allegations were very damaging to his career.
Constant criticism is damaging to a child’s self-esteem.
detrimental formal causing harm or having a bad effect on something:
Employers are worried that the new laws will have a detrimental effect on their business.
chemicals that are detrimental to the environment
policies that have been detrimental to the interests of old people
negative a negative effect is one that is bad and causes problems:
The car tax had a negative effect on car sales.
the negative impact of the recession in the US
hazardous hazardous substances are likely to be dangerous to people’s health and safety:
Hazardous waste needs to be disposed of safely.
hazardous chemicals
toxic toxic substances, smoke etc are poisonous:
toxic waste
toxic fumes
Toxic chemicals spilled into the river.
pernicious /pəˈnɪʃəs $ pər-/ formal used about something that has a gradual bad effect which is not easy to notice, especially on people’s morals, or on their health:
the pernicious effects of violent video games
the pernicious effect of secondhand smoke

[TahlilGaran] English Thesaurus ▲

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 ▲