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

Household Chemicals Items that are too hazardous for general waste are recyclable. — Nafeesah Allen, Better Homes & Gardens, 31 July 2026

Instead, people are urged to contact their municipal household hazardous waste collection center, which may be able to dispose of them or can provide further guidance. — Sam Gillette, PEOPLE, 31 July 2026

The National Weather Service issued a warning this week for beachgoers on the West Coast to be on high alert for life-threatening rip currents and hazardous ocean conditions. — ABC News, 30 July 2026

As more airports become equipped with advanced CT scanners that use 3-D imaging to detect hazardous liquids, the liquid limit rule could be scrapped entirely. — Rachel Chang, Condé Nast Traveler, 30 July 2026