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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"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.
“When you live in a country where political powers are constantly in play, when you own a restaurant, you’re the person who’s hosting somebody who’s having a dangerous conversation,” explains Katerina.
From Los Angeles Times ● Jul. 14, 2026
If any part of that setup is defective, the consequences can be dangerous.
From The Wall Street Journal ● Jul. 13, 2026
“This shows just how irrational investor expectations are becoming, and that sets a dangerous precedent,” Puckrin said, adding that SK Hynix is vulnerable given how heavily retail investors drive the South Korean stock market.
From MarketWatch ● Jul. 13, 2026
Teams have scored against Norway's organised 4-5-1 through rotations and dangerous runs out wide.
From BBC ● Jul. 12, 2026
‘I think the kingfisher was telling us to be true to ourselves, to shine bright even when the world seems dark and dangerous and full of shadows,’ she said.
From "Code Name Kingfisher" by Liz Kessler
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.
