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.
Drainages are natural low-lying areas of land that can gather hot air and smoke and then generate intense drafts that drive a fire uphill with dangerous speeds.
From Los Angeles Times ● Aug. 11, 2026
But for Claire Sisk, a content creator and advocate who has distorted vision, this can be dangerous.
From BBC ● Aug. 11, 2026
He said seizing vehicles was intended to keep roads safe and deter dangerous driving.
From BBC ● Aug. 10, 2026
To prevent AI from becoming dangerous, the U.S. government should establish and enforce standards that eliminate or greatly reduce the possibility that AI models will engage in deception or jump their guardrails.
From The Wall Street Journal ● Aug. 10, 2026
As long as he concentrated on that little game, he didn’t have to think about the fact that he and Katherine and Chip were about to do something incredibly stupid and probably dangerous as well.
From "Found" by Margaret Peterson Haddix
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.
