1. <convention> A word used in electronic mail and news messages to tag utterances as surrealist mind-play or humour, especially in connection with Discordianism and elaborate conspiracy theories. "I heard that David Koresh is sharing an apartment in Argentina with Hitler. (Fnord.)" "Where can I fnord get the Principia Discordia from?"
The word "fnord" was invented in the "Illuminatus!" trilogy by Robert Shea and Robert Anton Wilson.