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

Snow can cause travel disruptions and create hazardous driving conditions. —Joe Edwards, Newsweek, 7 Jan. 2025

Watch aftermath of multi-vehicle highway crash Region faces slick roads after winter storm The region was among several areas facing hazardous travel conditions due to a winter storm that battered the Midwest and the Mid-Atlantic over the weekend. —Anthony Robledo, USA TODAY, 7 Jan. 2025

Piercing cold with wind chills of 10 degrees below zero has gripped the Kansas City area, creating hazardous conditions across the metro, according to the National Weather Service. —Robert A. Cronkleton, Kansas City Star, 7 Jan. 2025

Another weather warning The weather service also noted hazardous marine conditions such as a high rip current risk for beaches across Broward and Palm Beach County Monday and lingering through the week. —Howard Cohen, Miami Herald, 6 Jan. 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