adjective
Other Word Forms
Derived 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.
“It can be a very dangerous situation,” Trudeau said.
From Los Angeles Times • Jun. 6, 2026
They point to climate change, aging water infrastructure, and weak monitoring systems as factors that could allow dangerous amoebae to spread and become harder to control.
From Science Daily • Jun. 6, 2026
The Canaries -- Spanish islands off the coast of west Africa -- have become the main entry point for irregular migrants into Spain after long and dangerous trips from Africa.
From Barron's • Jun. 6, 2026
Not only was he leaving the game, but the alliance would also be making a dangerous journey to a new part of space, as its new leaders wanted a fresh start.
From BBC • Jun. 5, 2026
It was a good idea—they were trying to keep people away from what could be a very dangerous situation.
From "Mountain of Fire" by Rebecca E. F. Barone
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.
