Simple Definition of hazardous

from our Learner's Dictionary

hazardous

adjective

ˈhæzɚdəs

: involving risk or danger : dangerous

It was a hazardous voyage.

These are hazardous chemicals that can cause death if inhaled.

hazardous driving habits

—sometimes + to

Smoking can be hazardous to your health.

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“Hazardous.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/hazardous. Accessed 20 Jun. 2026.

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