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

The Dali was carrying products including paper, U.S. soybeans destined for China and some hazardous materials, according to Concirrus, a marine insurance data provider, and DG Global, an agricultural exporter with goods on the ship. —Peter Eavis, New York Times, 5 Apr. 2024

Last year an inspection at the Legislative Office Building at 1020 N St. found hazardous materials such as acetylene had been moved there without a permit. —Theresa Clift, Sacramento Bee, 4 Apr. 2024

Adam Ortiz, the Environmental Protection Agency’s mid-Atlantic Regional Administrator, said there is no indication of active releases from the ship, nor of the presence in the water of materials hazardous to human health. —Lea Skene, Fortune, 30 Mar. 2024

While processing the lab, a team from the county’s hazardous materials program found a possible explosive compound stored in three containers, the sheriff’s office said. —Jason Green, The Mercury News, 29 Mar. 2024

During the update, an official from the Environmental Protection Agency addressed one of the most pressing concerns about the Dali: its 764 tons of hazardous materials that remain onboard. —Danny Nguyen, Washington Post, 29 Mar. 2024

Now, reports from the National Transportation Safety Board have confirmed that 56 containers on that ship were carrying hazardous material. —Elizabeth Blackstock / Jalopnik, Quartz, 29 Mar. 2024

The Weather Service issued a hazardous weather outlook on Friday morning for most of western and central Missouri, as well as eastern Kansas. —Eleanor Nash, Kansas City Star, 29 Mar. 2024

And hazardous materials that are not allowed in the tunnels will be diverted on a longer detour. —Mark Thompson, CNN, 27 Mar. 2024

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