often attributive
: a material (such as flammable or poisonous material) that would be a danger to life or to the environment if released without precautions

Did you know?

The origin of "hazmat" is clear enough - it was formed by combining the first three letters of each of two words: "hazardous" and "material." The word hazmat is fairly young, first appearing in print in 1980. Although it is a noun, "hazmat" tends to be used attributively, meaning that it often appears in sentences before another noun as if it were performing the duties of an adjective (as in "hazmat team" and "hazmat worker").

Examples of hazmat in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The shelter-in-place order has been lifted, and the evacuation zone has been reduced to a quarter-mile radius around the hazmat site on Thursday morning. — Jack Springgate, CBS News, 22 Oct. 2026 First responders, hazmat and safety teams are not approaching the tank because of the risk of more explosions, and will reassess conditions later Wednesday morning, Kapszukiewicz said. — John Seewer, Los Angeles Times, 21 Oct. 2026 Investigators could be seen wearing various levels of safety equipment, including face masks, hazmat suits, rubber gloves, protective sleeves and booties. — Michael Ruiz, FOXNews.com, 16 Oct. 2026 Colorado State Patrol’s hazmat team responded to the incident with local fire crews to contain and mitigate the fuel spill, agency officials said. — Lauren Penington, Denver Post, 6 Oct. 2026 See All Example Sentences for hazmat

Word History

Etymology

hazardous material

First Known Use

1972, in the meaning defined above

Time Traveler
The first known use of hazmat was in 1972

Browse Nearby Words

Podcast

Cite this Entry

“Hazmat.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hazmat. Accessed 27 Oct. 2026.

Medical Definition

hazmat

noun
haz·​mat
ˈhaz-ˌmat
often attributive
: a material (as radioactive, flammable, explosive, or poisonous material) that would be a danger to life or to the environment if released without necessary precautions being taken
toxic waste hauled away by workers in hazmat suits—Tom Spousta
hazmat storage
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster