hazardous

adjective
haz·​ard·​ous | \ ˈha-zər-dəs How to pronounce hazardous (audio) \

Definition of hazardous

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

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Other Words from hazardous

hazardously adverb
hazardousness noun

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

These materials are hazardous if improperly discharged. Bruce Murphy, The Verge, "Wisconsin’s $4.1 billion Foxconn boondoggle," 29 Oct. 2018 Planes were warned of the ash clouds because volcanic ash is hazardous for their engines. Fox News, "Volcano erupts on same Indonesian island as earlier quake," 3 Oct. 2018 Breathing in Houston can be hazardous to your health. Alex Park, Houston Chronicle, "Air pollution poses health risk to Houstonians, study finds," 3 July 2018 While the lure of taking a picture or video that goes viral on social media is strong, officials say the lava areas are still hazardous. Chris Morris, Fortune, "Hawaiian Tourists Face Up to $5,000 Fine for Taking Volcano Pictures," 18 June 2018 Breathing laze plumes can be hazardous, causing a range of effects that include lung damage and irritation of the eyes and skin. Maya Wei-haas, Smithsonian, "A Brief Glossary of Volcano Vocab," 25 May 2018 This cuspate ash, as it’s called, is hazardous to humans in two ways. Nsikan Akpan, Scientific American, "Kilauea’s Lava Is Now Spilling into the Ocean. Here’s Why That’s Dangerous," 22 May 2018 Offering a test for Down syndrome alongside tests for conditions like HIV reinforces the idea that this syndrome is hazardous. Chris Kaposy, STAT, "Children with Down syndrome live good lives. Prenatal testing shouldn’t nudge parents toward pregnancy termination," 18 May 2018 That’s almost double the upper limit of what’s considered hazardous. Umair Irfan, Vox, "New Delhi is once again the most polluted city on Earth," 8 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hazardous.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of hazardous

1549, in the meaning defined at sense 1

History and Etymology for hazardous

see hazard entry 1

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Statistics for hazardous

Last Updated

23 Mar 2019

Look-up Popularity

Time Traveler for hazardous

The first known use of hazardous was in 1549

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More Definitions for hazardous

hazardous

adjective

English Language Learners Definition of hazardous

: involving risk or danger

hazardous

adjective
haz·​ard·​ous | \ ˈha-zər-dəs How to pronounce hazardous (audio) \

Kids Definition of hazardous

: dangerous sense 1 hazardous chemicals

hazardous

adjective
haz·​ard·​ous

Legal Definition of hazardous

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

Other Words from hazardous

hazardously adverb

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Comments on hazardous

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