hazardous

[haz-er-duhs]

adjective

1. full of risk; perilous; risky.

   a hazardous journey.

   Synonyms: unsafe, dangerous
   Antonyms: secure, safe

2. dependent on chance.

   Synonyms: speculative, risky, uncertain, chancy
   Antonyms: sure, reliable, certain

hazardous

/ ˈhæzədəs /

adjective

1. involving great risk

2. depending on chance

Other Word Forms

• hazardously adverb
• hazardousness noun
• nonhazardous adjective
• nonhazardously adverb
• nonhazardousness noun
• ultrahazardous adjective
• unhazardous adjective
• unhazardously adverb

Word History and Origins

Origin of hazardous¹

First recorded in 1570–80; hazard + -ous

Example Sentences

UN3439 was much harder to identify because it is an umbrella code for a whole range of industrial chemicals, all of which are hazardous.

Read more on BBC

Most started falling ill in October, when the capital's air quality dipped to hazardous levels and waiting times for doctor's appointment had stretched longer than usual.

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The incident was declared a major emergency as 186 personnel were deployed to the scene of the hazardous material fire wearing protective gear such as body suits and oxygen masks.

Read more on Los Angeles Times

Airlines have canceled flights to Venezuela after the Federal Aviation Administration warned of a “potentially hazardous situation” there.

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Another goal is to decrease the use of hazardous chemicals and reduce the size and energy demand of hardware by applying advanced predictive technologies for high-power vortices.

Read more on Science Daily

Related Words

• dicey 
• difficult 
• perilous 
• precarious 
• risky 
• uncertain 
• unhealthy 
• unsafe 
• unsound