Merium-Webster said “fnord” was not in the dictionary.
No, at least not in most.
From Bing
Fnord is a word used in newsgroup and hacker culture to indicate that someone is being ironic, humorous or surreal. Often placed at the end of a statement in brackets (fnord) to make the ironic purpose clear, it is a label that may be applied to any random or surreal sentence, coercive subtext, or anything jarringly out of context (intentionally or not).
I did not know that definition. I was taught the theory/metaphor that “fnord” was something programmed into us early in school. You wouldn’t remember it and when you saw the word again it wouldn’t consciously register. You would experience anxiety though. Newspapers and TV would include the word thereby keeping the populace stressed.
Everybody knows the fnord is where Nessie dwells. I did a presentation on that very subject in Grad School at M.I.T. when I was achieving my doctorate Round Earth studies. I have a video of my presentation if you're interested.
Bagster
The Lesser Oracle
From:https://whatis.techtarget.com/definition/fnord
"Certain words are intended to be undefinable and "fnord" is one of them. First used in Robert Anton Wilson'[s] trilogy, The Illuminati Papers..."
<SNIP>
"In Wilson's trilogy, (based on reports from users), truth is revealed to those who know where to look. The enlightened can see fnord in the empty spaces between unjustified columns of text in newspapers and magazines. Called sticky spots, these spaces are not really blank, but contain fnord, visible only to those privy to heavily guarded secrets and occult powers."
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Basically, "fnord" are words that exist where there is nothing...
TXnMA
The word is often used in newsgroup and hacker culture to indicate that someone is being ironic, humorous, or surreal.[1] Often placed at the end of a statement in brackets (fnord) to make the ironic purpose clear, it is a label that may be applied to any random or surreal sentence, coercive subtext, or anything jarringly out of context (intentionally or not). It is sometimes used as a metasyntactic variable in programming.[2] It appears in the Church of the SubGenius recruitment film Arise! and has been used in the SubGenius newsgroup alt.slack.[citation needed]