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.
"They look a really dangerous team, they look fit, they look sharp, they look hungry," ex-Liverpool midfielder Danny Murphy said on BBC Match of the Day following the USA's excellent first-half performance.
From BBC • Jun. 13, 2026
Adoration of leaders can be dangerous and should not be a part of rational analysis.
From Barron's • Jun. 12, 2026
Queries about dangerous topics such as cybersecurity or bioweapons will be steered to an older Opus model.
From The Wall Street Journal • Jun. 11, 2026
A dangerous tapeworm that has been spreading across North America has now been detected in the Pacific Northwest, according to new research.
From Science Daily • Jun. 11, 2026
‘Watch out for soldiers. And don’t go anywhere dangerous.’
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.
