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

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

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

He spent 11 years at Old Trafford - his 237 goals in 404 appearances placed him third in United's player history list behind Wayne Rooney and Bobby Charlton.

From BBC • Dec. 31, 2025

We don’t talk much after what happened the first Christmas we spent in apartment 404.

From "Everything Sad Is Untrue" by Daniel Nayeri