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

In 2025, independent journalism platform Dialogue Earth documented hazardous working conditions—including exposure to toxic chemicals—at tanneries in India’s Tamil Nadu region that received the same sterling rating. —Jasmin Malik Chua, Footwear News, 1 Apr. 2026

What counties are included in the hazardous weather outlook? —Katie Wiseman, IndyStar, 31 Mar. 2026

Boating conditions are hazardous, but will continue to improve throughout the day. —Garfield Hylton, The Orlando Sentinel, 31 Mar. 2026

For example, several of our focus group participants in one neighborhood noted that gentrification was connected to the demolition of old buildings that likely contained hazardous substances, such as asbestos and lead. —Isaac Quaye, The Conversation, 30 Mar. 2026