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Showing results for hazardous. Search instead for hazarders.
Synonyms

hazardous

American  
[haz-er-duhs] / ˈhæz ər dəs /

adjective

  1. full of risk; perilous; risky.

    a hazardous journey.

    Synonyms:
    unsafe, dangerous
    Antonyms:
    secure, safe
  2. dependent on chance.

    Synonyms:
    speculative, risky, uncertain, chancy
    Antonyms:
    sure, reliable, certain

hazardous British  
/ ˈhæzədəs /

adjective

  1. involving great risk

  2. depending on chance

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • hazardously adverb
  • hazardousness noun
  • nonhazardous adjective
  • nonhazardously adverb
  • nonhazardousness noun
  • ultrahazardous adjective
  • unhazardous adjective
  • unhazardously adverb

Etymology

Origin of hazardous

First recorded in 1570–80; hazard + -ous

Explanation

The noun "hazard" means something dangerous, and the adjective hazardous refers to anything that involves danger. A golf course with lots of sand traps is especially hazardous for golfers. That's why those traps are called hazards. If your car blows a tire in the middle of the night, make sure to turn on your hazard lights. Being invisible to other drivers is hazardous to everyone, especially yourself. Life is, by definition, hazardous. It's full of dangers, both obvious and otherwise. Acknowledge that fact and keep going anyway. If you spend all your time focusing on what's hazardous, you end up missing all the wonderful things in life.

Keep Reading on Vocabulary.com

Vocabulary lists containing hazardous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Opponents have told the government it would be a breach of a 1998 convention signed by Australia to ship hazardous waste to a Pacific island country.

From Barron's • Apr. 22, 2026

"It cannot be ruled out that a hazardous substance was introduced... due to external influence," it said.

From BBC • Apr. 18, 2026

The suit alleged the turbines emit pollution and hazardous chemicals that have been linked to increases in asthma, respiratory diseases, heart problems and certain cancers.

From The Wall Street Journal • Apr. 14, 2026

The memoir of a former New York City subway motorman details his hazardous workdays below the streets.

From The Wall Street Journal • Apr. 10, 2026

You could even reclaim a hazardous waste dump.

From "Blood of Olympus" by Rick Riordan