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.
With temperatures at 14 of the 16 host venues set to exceed dangerous levels according to researchers, there were fears this bottle ban could put fans' health at risk.
From BBC • Jun. 9, 2026
The new one is better, but the thinking behind it still rests on a dangerous confusion.
From The Wall Street Journal • Jun. 9, 2026
That began with the shocked roar that met Rush’s first number, 1977’s “Xanadu,” a chugging slab of custom-van-tested shag splendor, akin to kicking off a trick show with the most dangerous stunt.
From Los Angeles Times • Jun. 8, 2026
Umar Ben Yusaf, 35, and Abubakr Ben Yusaf, 31, deny causing death by dangerous driving and causing serious injury by dangerous driving.
From BBC • Jun. 8, 2026
‘He can’t come. We can’t risk it. This mission is already dangerous enough.’
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.
