Fnord
A word originally meaning a small exotic fish (although this is disinformation) it now epitomises meaninglessness, which paradoxically identifies the user as a discordian. Blame H.P. Lovecraft and the Illuminatus Trilogy by Robert Anton Wilson + Robert Shea.
Fnord can often be [ab]used as a metasyntax variable.
A very enlightening reading about fnords can be found on www.fnord.org . Principia Discordia is also keen on fnords.