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.
“The most dangerous course of action right now is to stand still and to remain in a human-driven world,” Stanley said.
From The Wall Street Journal • Jun. 19, 2026
Doctors warn that measles is especially dangerous for babies who are too young to be vaccinated.
From Los Angeles Times • Jun. 19, 2026
"The ground there is cracked, and the cracks are long. That is why this area would be very dangerous if another earthquake as strong follows," he said.
From Barron's • Jun. 19, 2026
In the BBC documentary series, he travels to some of the world's most dangerous places, interviewing young men who live on the fringes of society.
From BBC • Jun. 18, 2026
“I would climb mountains and traverse dangerous cliff paths. I would poke my head into dark caves and push over heavy boulders.”
From "The Very, Very Far North" by Dan Bar-el
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.
