Synonyms of hazardous

hazardous

adjective

ˈha-zər-dəs 

as in dangerous

involving potential loss or injury

a hazardous journey across the arctic ice

Synonyms & Similar Words

• dangerous
• perilous
• risky
• serious
• unsafe
• precarious
• treacherous
• menacing
• unhealthy
• threatening
• venturesome
• grave
• grievous
• random
• parlous
• fatal
• harmful
• destructive
• detrimental
• jeopardizing
• uncertain
• unpleasant
• adverse
• bad
• lethal
• deadly
• insecure
• sickening
• injurious
• haphazard
• ultrahazardous
• dicey
• chance
• deleterious
• distressing
• ugly
• murderous
• malignant
• noxious
• pernicious
• nasty
• fell
• evil
• wicked
• baneful
• hurtful
• killer
• inimical
• dire
• ill
• mortal
• fateful
• deathly
• baleful
• pestilent

Antonyms & Near Antonyms

• safe
• harmless
• nonhazardous
• innocuous
• innocent
• beneficial
• nonthreatening
• good
• advantageous
• unthreatening
• ultrasafe

Synonym Chooser

How is the word hazardous distinct from other similar adjectives?

Some common synonyms of hazardous are dangerous, perilous, precarious, and risky. While all these words mean "bringing or involving the chance of loss or injury," hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

When is dangerous a more appropriate choice than hazardous?

In some situations, the words dangerous and hazardous are roughly equivalent. However, dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

When could perilous be used to replace hazardous?

Although the words perilous and hazardous have much in common, perilous strongly implies the immediacy of danger.

perilous mountain roads

In what contexts can precarious take the place of hazardous?

While the synonyms precarious and hazardous are close in meaning, precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

Where would risky be a reasonable alternative to hazardous?

While in some cases nearly identical to hazardous, risky often applies to a known and accepted danger.

shied away from risky investments

Example Sentences

Recent Examples of hazardous

Emmet Pierson, president of Community Builders, has said that rampant crime in the area has been a deterrent for customers and created hazardous working conditions for the store’s employees. —David Hudnall, Kansas City Star, 24 Apr. 2025

And like the previous trials, the intense tests served an important purpose—in this case, making sure the shields coating LIFE habitat modules will withstand any hazardous micrometeoroid and orbital debris (MMOD) impacts. —Andrew Paul, Popular Science, 24 Apr. 2025

Ranging from 0 to 500, the AQI is used to measure air pollution levels and to alert the public when pollutant levels may make the air hazardous to health. —Muri Assunção, New York Daily News, 24 Apr. 2025

Allowed to crumble into disrepair by its owners, the Meruelo family, the famous hotel was ordered demolished by the city as a hazardous structure. —Andres Viglucci, Miami Herald, 24 Apr. 2025