hazardous

adjective

haz·​ard·​ous ˈha-zər-dəs 

1

: involving or exposing one to risk (as of loss or harm)

a hazardous occupation

disposing of hazardous waste

2

: depending on the effect of unpredictable and unanalyzable forces in determining events : depending on hazard (see hazard entry 1 sense 2a) or chance

hazardous outcomes

hazardously adverb

hazardousness noun

Synonyms

• dangerous
• grave
• grievous
• jeopardizing
• menacing
• parlous
• perilous
• risky
• serious
• threatening
• unhealthy
• unsafe
• venturesome

Choose the Right Synonym for hazardous

dangerous, hazardous, precarious, perilous, risky mean bringing or involving the chance of loss or injury.

dangerous applies to something that may cause harm or loss unless dealt with carefully.

soldiers on a dangerous mission

hazardous implies great and continuous risk of harm or failure.

claims that smoking is hazardous to your health

precarious suggests both insecurity and uncertainty.

earned a precarious living by gambling

perilous strongly implies the immediacy of danger.

perilous mountain roads

risky often applies to a known and accepted danger.

shied away from risky investments

Examples of hazardous in a Sentence

It was a hazardous voyage.

These are hazardous chemicals that can cause death if inhaled.

Recent Examples on the Web

However, the Cutler documentary project could examine a downside to seizing Greenland (apart from disrupting the NATO alliance): the site is strewn with hazardous material. —Matthew Carey, Deadline, 11 Feb. 2025

The way that the power cable loops out in some shots does look a bit hazardous, although it could presumably be tucked in better for out-on-the-street use. —Ben Coxworth, New Atlas, 10 Feb. 2025

Listen to this article Yet another winter storm hit the New York City area overnight, dumping up to 5 inches of snow across the region and creating hazardous travel conditions ahead of Super Bowl LIX Sunday. —Joseph Wilkinson, New York Daily News, 9 Feb. 2025

The National Weather Service (NWS) has issued a winter storm watch from Friday through Sunday, warning residents of hazardous conditions and potential travel disruptions. —Yaakov Katz, Newsweek, 7 Feb. 2025

Word History

Etymology

see hazard entry 1

First Known Use

1549, in the meaning defined at sense 1

Kids Definition

hazardous

adjective

haz·​ard·​ous ˈhaz-ərd-əs 

: dangerous sense 1, risky

hazardously adverb

hazardousness noun

Legal Definition

hazardous

adjective

haz·​ard·​ous

: creating a hazard : involving or exposing one to risk (as of loss or harm)

a hazardous occupation

a hazardous substance

hazardously adverb