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

The hazardous conditions could impact the Monday morning commute. —Kansas City Star Weather Bot, Kansas City Star, 16 Mar. 2026

Closer to Chicago, snow is expected to redevelop early this morning with 1 to 4 inches possible, though strong winds will still reduce visibility and make travel hazardous. —Albert Ramon, CBS News, 16 Mar. 2026

On May 2024, firefighters and a county hazardous materials crew responded to a fire in Otay Mesa at the 250-megawatt Gateway Energy Storage facility, operated by LS Power and its subsidiary, Rev Renewables. —Rob Nikolewski, San Diego Union-Tribune, 16 Mar. 2026

In addition to rain, forecasters expected 60 mile per hour winds in the Charlotte area, with hazardous conditions lasting through Monday morning. —Evan Moore, Charlotte Observer, 16 Mar. 2026