"Fnord" is a word coined in 1965 by Kerry Thornley and Greg Hill in the Discordian religious text Principia Discordia. It entered into popular culture after appearing in The Illuminatus! Trilogy (1975) of novels written by Robert Shea and Robert Anton Wilson. Here, the interjection "fnord" is given hypnotic power over the unenlightened, and children in grade school are taught to be unable to see the word consciously. For the rest of their lives, every appearance of the word subconsciously generates a feeling of unease and confusion which prevents rational consideration of the text in which it appears.

The Principia Discordia is the first published Discordian religious text. It was written by Greg Hill with Kerry Wendell Thornley and others. The first edition was printed using Jim Garrison's Xerox printer in 1963. The second edition was published under the title Principia Discordia or How The West Was Lost in a limited edition of five copies in 1965. The phrase Principia Discordia, reminiscent of Isaac Newton's 1687 Principia Mathematica, is presumably intended to mean Discordant Principles, or Principles of Discordance.