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
Words Every Pirate Should Know
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
"Volcano!"
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
"Brothers in Hope"
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Law enforcement officials also point out that any type of modification to e-bikes might not just be dangerous, but can also transform the e-bike into a motorcycle or moped under California law.
From Los Angeles Times • Jun. 10, 2026
Coal mines often leach dangerous chemicals like arsenic into waterways and are required to strictly monitor pollution discharge and keep it under certain limits.
From Salon • Jun. 10, 2026
They have got some excellent technical players and will be dangerous, whoever they play.
From BBC • Jun. 10, 2026
The large language model called Claude Fable 5 will mostly let users query Mythos, which the company previously deemed too dangerous for general release.
From The Wall Street Journal • Jun. 9, 2026
Duane was exposed and vulnerable to a most dangerous situation.
From "The Very, Very Far North" by Dan Bar-el
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.
