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.
The Dow Jones Industrial Average fell 404 points, or 0.8%, while the S&P 500 was off 0.9%.
From Barron's • Mar. 7, 2026
A Ring spokesperson defended the Search Party tool when reached for comment by 404.
From Salon • Feb. 18, 2026
The BBC has asked 280 Labour MPs of the 404 currently sitting in Parliament what their views were on Burnham attempting to become an MP again.
From BBC • Jan. 23, 2026
The app’s existence was earlier reported by 404 media, a digital publication focused on technology and privacy.
From The Wall Street Journal • Jan. 5, 2026
Olanna watched the Peugeot 404 disappear down the road and stood there for a while, feeling as if she had swallowed a sparkling sliver of light.
From "Half of a Yellow Sun" by Chimamanda Ngozi Adichie
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.
