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.
The report didn’t describe Fable producing more dangerous products, such as “exploit” software that could be used in a cyberattack, according to cybersecurity experts who had viewed the research.
From The Wall Street Journal • Jun. 14, 2026
As he writes in “Cross Purposes: Christianity’s Broken Bargain with Democracy,” “Christianity is a load-bearing wall; its failure places dangerous stress on democratic institutions.”
From Salon • Jun. 14, 2026
Coastal Southern California must still endure a particularly dry June before reaching typical conditions July through September — and even “typical” conditions remain dangerous, which is why officials urged Southern Californians Friday to remain vigilant.
From Los Angeles Times • Jun. 13, 2026
Before the models were released, Anthropic warned that Mythos was so powerful that it could potentially be dangerous in the hands of bad actors.
From MarketWatch • Jun. 13, 2026
"Driving to work every day is dangerous enough," she had told Jeremy that night.
From "Jeremy Thatcher, Dragon Hatcher" by Bruce Coville
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.
