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

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.

Read more on BBC

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.

Read more on Los Angeles Times

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

A major emergency was declared at the Port of Los Angeles on Friday night as 186 firefighters worked to combat a massive and stubborn blaze involving hazardous materials on a cargo ship, authorities said.

Read more on Los Angeles Times

Related Words

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