Dead, a term used in a popular roleplaying application known as "Geeking", the term is used to identify chats that have been inactive for a very long time, (two to four weeks or more) though, a majority of the community uses the word improperly, instead making it one of the many annoyances of the community.
*Chat that has been inactive for only a few minutes or an hour.*
Random User: "Dead."
User: "Oh god-- one of you."
Another User: "It's only been thirty minutes, moron."