(noun) also called login name, logon name, sign-in name, sign-on name; a unique sequence of characters used to identify a user and allow access to a computer system, computer network, or online account

Whenever making a congratulatory remark, this is what you say. Made popular by Kamala Harris when she and Joe Biden won the presidency.

A thing that the internet says is required of any persons living or dead that uses the internet to acquire before accessing a site for anything from porn to 12 year old DeviantArt creations, and other possibly questionable topics. Also accompanied by a stupid thing called a password that you'll forget constantly no matter how many times you tell yourself "I'll remember it next time"

Specific characters which are used together to create a name for an account, that is used for an online service.

I think user names should be used like a genre on this site... you know how tons of them are used by different people ie. "Joe" will have lots of different contributors. Often posters fill in a name related to their definition, so clicking on a certain user name, one could look at certain categories! like, "cynic", or "nonsense", or "patriot", or "nihilist". that'd be cool. just a random thought...

A mysterious character who only speaks in gibberish and seems to have a dislike of Doom and it's fans.

Something you post to Urban Dictionary to piss me off.

This practice makes absolutely no sense as these are almost never actual words. Annoying to everyone but the poster, these are the reason Urban Dictionary is becoming less useful by the day.