404 Not Found 

The screen of death

Oh shit, I just typed my website wrong and it says "404 Not Found". I hate the internet.

404 Not Found by Ashabeth October 20, 2008

404'd 

Homestarrunner.com's way of showing you fools how to use the internet... 404ing your ass!

<CHILDREN!> 404'd!
<Ugly> Ow, my browser!

404'd by Bastardized Bottomburp June 18, 2003

404 Error 

a webite spinoff of Life, the Universe, and Everything.

404 > Life, the Universe, and Everything.

404 Error by just a guy December 14, 2003

404 Not Found 

404 Not Found is the completely fucking retarded screen that comes up whenever you're looking for a good porn trailer.

AWW, SHIT! I GOT THE FUCKING 404 NOT FOUND CRAP AGAIN AND LOST MY PORN!

404 Not Found by worn.down April 25, 2010

404 girl 

A green haired cartoon girl appearing on the 4chan website.

As Jimmy attempted to view a post that had been deleted on 4chan he was confronted with the 404 girl.
"Oh Lawd!! I've been 404'd!!" thought Jimmy.

404 girl by Lord Afroduck November 7, 2007

404 - Unable to Woo

When a nerd tries to hit on someone out of his league and gets rejected. The nerd is therefore unable to woo the person he is hitting on. Frequently comes in the form of a disgusted facial expression or the person walking away from the nerd looking like they saw a ghost.

Named after the infamous 404 web page error that occurs when the page is unavailable.

Alex tried to offer the woman a beer but instead got a 404 - Unable to Woo when he approached her.

404 - Unable to Woo by CL_FlushEntity June 11, 2006

404'd 

When your significant other won't let you in the back door.

"Hey, did you get some last night?"
"I did, but when I tried to go in back door, my dick got 404'd"

404'd by KUJ August 3, 2016