I remember the basic definition of this word, but I can't remember the word itself. To paraphrase the definition (if I remember correctly):
To include many unnecessary details with the objective of making a story or narrative seem more convincing or believable.
The correct answer will be a long, complicated word not ever used in everyday speech. It could also be a non-verb that encompasses that basic idea.
Just to provide more context. This is going to be a tough one. I've never ever heard this word used in real life. It was introduced to me when I noticed at a climbing gym; one of the routes had this word as its name. Later that night I went home and looked up the word, which revealed something similar to the above definition. Since then I have not seen the word, and since then the route has changed :/
I'm fairly accomplished at Google-fu, so I wouldn't recommend trying to answer this with a cursory scan of Google. I already spent quite a bit of time on that approach. At this point I'm really just hoping somebody on here is a professor or something with some very esoteric knowledge of obscure English words and happens to recognize it.
A couple of people have suggested Verisimilitude. This is very close. What I'm looking for is a word which describes embellishing or embroidering a story or narrative with the end result being verisimilitude. I suspect that although difficult, verisimilitude could be achieved without the embellishment or embroidery of details, and therein lies the difference between verisimilitude and this word.