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 Florida Forever, a state land-buying conservation program; $100 million to help clean up Piney Point, the site of a leak of hazardous material in Sarasota; and $500 million to move houses on septic systems to sewer systems. Gray Rohrer, orlandosentinel.com, "State budget tops $101.5 billion, bolstered by federal COVID aid," 27 Apr. 2021 The regulatory body responsible for investigating the incident remains unclear because nurdles are not classified as a hazardous material. Washington Post, "Huge plastics plant faces calls for environmental justice, stiff economic headwinds," 19 Apr. 2021 Officials worry that the collapse of the system could spew polluted water as well as more hazardous material into the area and bay. sun-sentinel.com, "Leak at wastewater pond, potential collapse of radioactive stacks prompt evacuations near Bradenton," 3 Apr. 2021 In Mississippi, residents now know a biodiesel plant is accused of illegally dumping hazardous material into public waterways. Gene Policinski, Milwaukee Journal Sentinel, "Opinion: There can be no American democracy without a free press," 16 Mar. 2021 There is no engine, fuel tanks or hazardous material on the boat, the club added. Frank Witsil, Detroit Free Press, "100-year-old tugboat being used as Bayview Yacht Club's temporary clubhouse sinks," 15 Mar. 2021 As the News noted in its anniversary package, since then, another 470,000 gallons of of petroleum, gas or hazardous material were leaked by faulty infrastructure across the state, with Colonial responsible for 19 of those incidents. Nick Martin, The New Republic, "How a Gas Company Spent 2020 Denying One of the Biggest Pipeline Spills in American History," 1 Mar. 2021 According to the Bellona, the Northern Fleet also jettisoned 17,000 containers of hazardous nuclear material and deliberately sunk 19 vessels packed with radioactive waste, along with 735 contaminated pieces of heavy machinery. Cory Graff, Popular Mechanics, "The Terrifying History of Russia’s Nuclear Submarine Graveyard," 17 Jan. 2021 Disposing of industrial, military, nuclear and other hazardous waste was a pervasive global practice in the 20th century, according to researchers. Julie Watson, chicagotribune.com, "Scientists find what they believe to be massive underwater toxic waste dump containing DDT off the California coast," 27 Apr. 2021

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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Time Traveler for hazardous

Time Traveler

The first known use of hazardous was in 1549

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Statistics for hazardous

Last Updated

12 May 2021

Cite this Entry

“Hazardous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hazardous. Accessed 18 May. 2021.

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More Definitions for hazardous



English Language Learners Definition of hazardous

: involving risk or danger


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

Kids Definition of hazardous

: dangerous sense 1 hazardous chemicals



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

Comments on hazardous

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