404
Americannoun
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Also called 404 error. Computers. an error message sent by a web server to a browser when the user has typed an incorrect URL, tried to access a web page that is no longer available, or clicked on a broken link on a web page.
They must have taken down their website;
I keep getting that annoying “404 - File Not Found” message.
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Slang. a person who is stupid or uninformed.
noun
Etymology
Origin of 404
First recorded in 1995–2000
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.
These AI influencers "are mostly young white women," said Emanuel Maiberg of the 404 Media tech news outlet who has covered the trend.
From Barron's • Mar. 27, 2026
The Dow fell for a third-straight session, closing Tuesday down 0.8%, or around 404 points.
From The Wall Street Journal • Mar. 3, 2026
The company’s data-sharing with federal authorities and cybersecurity lapses have been documented by 404 Media and other outlets.
From Los Angeles Times • Mar. 1, 2026
Leaked emails obtained by 404 Media strongly suggest that Ring’s pet lookup tools would be expanded, with the goal of helping “zero out crime in neighborhoods.”
From Salon • Feb. 20, 2026
Mari did, but a 404 error popped up.
From "Boy 2.0" by Tracey Baptiste
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.
