I found the phrase “My sincerest contrafibularities, Tim” given to one of the comments to my question about the word, 'Cromulent' in EL&U site.
As I was totally unfamiliar with the word, ‘contrafibularities’ (as well as 'Cromulent'), I checked Cambridge, Oxford, and Merriam-Webster online dictionary. None of them registers ‘Contrafibularities.’ GoogleNgram doesn’t carry this word either.
However, I was able to find the definition of this word as ‘A form of congratulations as used by Edmund Blackadder to mock Doctor Samuel Johnson, author of the dictionary’ in www.urbandictionary.com, and its origin;
Blackadder: "Allow me to be the first to offer Dr. Johnson my most sincere contrafibularities! I am anaspeptic ... Contrafibularities: Obviously from contra, against, + fibula, the smaller of the two bones in the lower leg. Means 'pulling one's leg,' in www.reviewers-choice.com.
I don’t understand why combination of prefix ‘contra’ and ‘fibula’ come to form the meaning of ‘Congratulations.’
But as it looks like the salute giver used this word quite casually (I think) to congratulate a comment poster, the word (contrafibularities) wouldn’t be any unusual word.
However, I would like to make sure of popularity and usability of this word. The word may be taken for granted as casually among native English speakers even among cab-drivers and burger-shop waitresses (I use these jobs just for the purpose of reffering to an average person).
But, if I speak this word in conversation with or use in writing to native speakers, am I ridiculed or jeered by them as being awkward?