adjective
Other Word Forms
- dangerously adverb
- dangerousness noun
- nondangerous adjective
- nondangerously adverb
- nondangerousness noun
- quasi-dangerous adjective
- quasi-dangerously adverb
- semidangerous adjective
- semidangerously adverb
- semidangerousness noun
- undangerous adjective
- undangerously adverb
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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"Brothers in Hope"
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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 campaign, which made Bukele hugely popular, has resulted in a dramatic decrease in crime, turning El Salvador from one of Latin America's most dangerous countries to one of its safest.
From Barron's • Apr. 20, 2026
The mites also spread dangerous viruses such as Deformed Wing Virus and Acute Bee Paralysis Virus by injecting them directly into a bee's bloodstream.
From Science Daily • Apr. 20, 2026
But Dressel wants to hold Bayer accountable and for the company to admit that it marketed a potentially dangerous product.
From The Wall Street Journal • Apr. 20, 2026
The in-race changes are mainly targeted at ensuring sudden speed differentials between cars in different deployment states do not become dangerous.
From BBC • Apr. 20, 2026
The way she calls my name makes my butterflies take up their flags, stand in a line like an army poised for battle — like what I’m about to walk into might be dangerous.
From "Red Flags and Butterflies" by Sheryl Azzam
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.
