• synonyms


[deyn-jer-uh s, deynj-ruh s]
See more synonyms for dangerous on Thesaurus.com
  1. full of danger or risk; causing danger; perilous; risky; hazardous; unsafe.
  2. able or likely to cause physical injury: a dangerous criminal.
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Origin of dangerous

1175–1225; Middle English da(u)ngerous domineering, fraught with danger < Old French dangereus threatening, difficult, equivalent to dangier (see danger) + -eus -ous
Related formsdan·ger·ous·ly, adverbdan·ger·ous·ness, nounnon·dan·ger·ous, adjectivenon·dan·ger·ous·ly, adverbnon·dan·ger·ous·ness, nounqua·si-dan·ger·ous, adjectivequa·si-dan·ger·ous·ly, adverbsem·i·dan·ger·ous, adjectivesem·i·dan·ger·ous·ly, adverbsem·i·dan·ger·ous·ness, nounun·dan·ger·ous, adjectiveun·dan·ger·ous·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for dangerous

treacherous, unhealthy, threatening, deadly, unsafe, terrible, precarious, ugly, bad, critical, unstable, alarming, serious, nasty, fatal, perilous, risky, breakneck, chancy, delicate

Examples from the Web for dangerous

Contemporary Examples of dangerous

Historical Examples of dangerous

  • What a dangerous character you'd be if you were sent to match silks!

    The Spenders

    Harry Leon Wilson

  • Philip was getting into a dangerous mood with his sentimentalism.


    Thomas Wentworth Higginson

  • My dear, I'm glad and thankful you've done with that dreadful, dangerous game.

  • Such conduct is as wicked and dangerous to the state as any that can be conceived.

  • He had got a dangerous game to play, and his plans were vague and shadowy.

    Life in London

    Edwin Hodder

British Dictionary definitions for dangerous


  1. causing danger; perilous
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Derived Formsdangerously, adverbdangerousness, 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 dangerous


early 13c., "difficult, arrogant, severe" (the opposite of affable), from Anglo-French dangerous, Old French dangeros (12c., Modern French dangereux), from danger (see danger).

In Chaucer, it means "hard to please, reluctant to give;" sense of "full of danger, risky" is from late 15c. Other words used in this sense included dangersome (1560s), dangerful (1540s). Related: Dangerously.

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Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with dangerous


see little knowledge is a dangerous thing; live dangerously.

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The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.