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
Words Every Pirate Should Know
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"Volcano!"
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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.
The most dangerous words in investing are “This time it’s different,” warned celebrated fund manager John Templeton.
From Barron's • May 27, 2026
Because this kind of study can show an association but cannot prove cause and effect, the takeaway is not that B12 is dangerous.
From Science Daily • May 27, 2026
He voiced his rage over an empty reservoir, idled fire trucks and what he called dangerous brush clearance policies.
From Los Angeles Times • May 27, 2026
That means they are only going to get more creative and more dangerous, says Jake Braun, executive director of the Cyber Policy Initiative at the University of Chicago’s Harris School of Public Policy.
From The Wall Street Journal • May 26, 2026
Eventually she becomes at ease, convinced, at least enough, that me sitting in her seat hasn’t caused me to behave in any abnormal or dangerous ways, and that I don’t plan to ransack her workstation.
From "The Brightwood Code" by Monica Hesse
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.
