404

In real, traceable use. Part of the curated seed collection; community review is coming.

Meaning · English

Not found, especially of a web page on the Internet.

Register: slang

Where it’s used: Used American English

Examples

Bill was 404 all morning.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).

Common questions

What does “404” mean?

Not found, especially of a web page on the Internet.

Is “404” formal or informal?

404 is generally slang.