full of risk; perilous; risky: a hazardous journey.
dependent on chance.

Origin of hazardous

First recorded in 1570–80; hazard + -ous
Related formshaz·ard·ous·ly, adverbhaz·ard·ous·ness, nounnon·haz·ard·ous, adjectivenon·haz·ard·ous·ly, adverbnon·haz·ard·ous·ness, nounul·tra·haz·ard·ous, adjectiveun·haz·ard·ous, adjectiveun·haz·ard·ous·ly, adverb

Synonyms for hazardous

Antonyms for hazardous

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for hazardous

Contemporary Examples of hazardous

Historical Examples of hazardous

  • Of all the hazardous ventures in which the detective had been engaged, this was certainly not the least hazardous.

    Henry Dunbar

    M. E. Braddon

  • This is a strange and hazardous situation in which we are placed.

    Homeward Bound

    James Fenimore Cooper

  • Wherever he had elected to crouch and tremble, it was too hazardous to go near him.

  • The condition of his heart was hazardous and she had been told that any excitement might be fatal.

    The Paliser case

    Edgar Saltus

  • The descent was as anxious and hazardous as the ascent had been laborious.

British Dictionary definitions for hazardous



involving great risk
depending on chance
Derived Formshazardously, adverbhazardousness, noun
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

Word Origin and History for hazardous

1580s, "venturesome;" 1610s, "perilous," from hazard (n.) + -ous or from Middle French hasardeux (16c.).

Online Etymology Dictionary, © 2010 Douglas Harper