adjective
Other Word Forms
Etymology
Origin of dangerous
First recorded in 1175–1225; Middle English da(u)ngerous “domineering, fraught with danger,” from Old French dangereus “threatening, difficult,” equivalent to dangier ( see danger) + -eus -ous
Explanation
Use the word dangerous to describe anything that can potentially cause serious harm, like a snarling pit bull or an icy, treacherous road. The earliest meaning of the word dangerous was "difficult or arrogant." When Geoffrey Chaucer wrote "The Canterbury Tales" in the 1300s, he used dangerous to mean "hard to please." Gradually the meaning changed, so that by the late fifteenth century, dangerous meant "liable to cause hurt" or "risky." Just as popular were two other danger-related words that we don't use anymore today: dangersome and dangerful, which at the time could be used interchangeably with dangerous.
Vocabulary lists containing dangerous
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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.
“That can be a dangerous combination,” he said.
From MarketWatch ● Sep. 2, 2026
The Leipzig attack was part of a broader pattern of increasingly dangerous incidents, including drones and interference with critical infrastructure, von der Leyen said.
From BBC ● Sep. 2, 2026
The Himalayan nation has limited resources to confront destruction on such a scale, and the disaster is stark warning of the dangerous fragility of its mountain environment in a rapidly heating world.
From Barron's ● Sep. 2, 2026
Car accidents are dangerous for everyone involved, but they have become even more hazardous for pedestrians and cyclists.
From Los Angeles Times ● Sep. 1, 2026
His deep, matter-of-fact tone made him seem all the more dangerous.
From "Will’s Race for Home" by Jewell Parker Rhodes
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
