404

American  

[fawr-oh-fawr] / ˈfɔr oʊˈfɔr /

noun

1. 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.

2. Slang. a person who is stupid or uninformed.

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404 British  

/ ˌfɔːəʊˈfɔː /

noun

1. slang a stupid or ineffectual person

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Etymology

Origin of 404

First recorded in 1995–2000

Example Sentences

Only around a third of Angus’s 404 owners have plied their tokenized shares of the animal into the artists’ online Remorse Portal, signifying their wish to save his life.

From The Wall Street Journal • Mar. 11, 2026

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

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