What is a long, complicated word for adding many unnecessary details to make a story seem more believable?

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.

Update

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.

Update 2

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.


Solution 1:

Verisimilitude -- this is a narrative technique of describing things in extremely accurate detail to make the fiction more believable, literally 'very similar to' real life!

Aside from being fun to say, verisimilitude (pronounced ‘VAIR-ih-sih-MILL-ih-tude’) simply means ‘the quality of resembling reality’ and a work of art, or any part of a work of art, has verisimilitude if it seems believably realistic. The word verisimilitude is derived from the Latin words verum and similis meaning “truth” and “similar.” A verisimilitudinous story has details, subjects, and characters that seem similar or true to real life.

SOURCE: https://literaryterms.net/verisimilitude/

Note: If you feel the details are unnecessary or excessive to achieve verisimilitude then you can say 'tedious verisimilitude' which is not a single-word but clearly expresses your sentiment. Example:

Mrs.P always overwhelms her readers with tedious verisimilitude. When she writes about a mining town I feel not as if I were in a mining town, but as though I were in a mining town in a Mrs.P novel -- too dreary and quite unbearable verisimilitude, more real than the real thing!

Option 2: An extremely detailed description can be called hyperdescriptive or hyper-descriptive, but this is usually intentional and the excessive detail is necessary, being intended for literary effect, as in this extract from James Joyce's Ulysses:

What did Bloom see on the range?

On the right (smaller) hob a blue enamelled saucepan: on the left (larger) hob a black iron kettle.

What did Bloom do at the range?

He removed the saucepan to the left hob, rose and carried the iron kettle to the sink in order to tap the current by turning the faucet to let it flow.

Did it flow?

Yes. From Roundwood reservoir in county Wicklow of a cubic capacity of 2400 million gallons, percolating through a subterranean aqueduct of filter mains of single and double pipeage constructed at an initial plant cost of £5 per linear yard by way of the Dargle...

Source: http://www.cforster.com/2010/06/when-david-foster-wallace/

Option 3: avalanche of detail is another term often used in this context:

Roberts buried his readers under an avalanche of detail.

Solution 2:

Since nobody proposed this yet, I'll just put it here, since I believe it's the most suitable, although OP has used this word in the question itself.

embellish

Sub-definition in Oxford Dictionary:

  • Make (a statement or story) more interesting by adding extra details that are often untrue

And the corresponding embellishment:

  • A detail, especially one that is untrue, added to a statement or story to make it more interesting.

Personally, I always see this word being used in negative context, which matches this second definition. Disclaimer: I'm a non-native speaker of English.

Solution 3:

  • circumlocution: the use of many words where fewer would suffice, especially in an attempt to deceive.
  • sesquipedalian: the use of long words for the sake of sounding important or detailed or meaningful.
  • loquaciousness: overly talkative and using many words (probably not this one but I threw it in just in case)
  • pleonasm: the use of more words than are necessary to convey meaning (e.g., see with one's eyes ), either as a fault of style or for emphasis.
  • tautology: the saying of the same thing twice in different words, generally considered to be a fault of style (e.g., they arrived one after the other in succession ).
  • rhetoric: language designed to have a persuasive or impressive effect on its audience, but often regarded as lacking in sincerity or meaningful content.

Those are ones I could think of quickly. Is it any of these?

Solution 4:

I suspect that the term you are seeking is a rhetorical device, such as hypotyposis. From The Century Dictionary and Cyclopedia, via Wordnik:

In rhetoric, vivid description of a scene or an event, as though it were present before the eyes of the audience; an oratorical word-picture.

Rhetoric is rich in terminology, and there are actually a number of plausible possibilities that seem worth investigation. Ann Vasaly mentions several in her Representations: Images of the World in Ciceronian Oratory:

rhetorical handbooks . . . advised [speakers] to use concrete details in order to create a "visual image" in the minds of his listeners. As mentioned in chapter 1, the technique can be found under a variety of names, and it is often identified with ekphrasis, enargeia, hypotyposis, diatyposis, evidentia, repraesentatio, illustratio, demonstratio, descriptio, and sub oculos subiectio. Further, it is subsumed under a number of theoretical categories, including techniques of the narration and of the peroration, aspects of ornate style, and figures of thought.

[Bolding added.]

Looking at some of these separately, either hypotyposis or enargeia seem likely. From Silva Rhetoricae (bolding added; note all definitions are at the same link; use search or the right navigation menu to go to the correct frame):

hypotyposis • ὑποτύπωσις

hy-po-ty-po'-sis from Gk. hypotypoein, "to sketch" (typos = "impression, form")
Also sp. hypotiposis
demonstratio, evidentia, adumbratio, representatio[,] the counterfait representation, word-picture
Synonym for enargia. Lively description of an action, event, person, condition, passion, etc. used for creating the illusion of reality.

And for enargia:

from Gk. enarges, "visible, palpable, manifest" diatyposis, hypotyposis[,] demonstratio, descriptio

Generic name for a group of figures aiming at vivid, lively description.

Ekphrasis might be a strong contender in its original rhetorical meaning; however, it is likely that any definition found in a standard dictionary today would contain the more specific, modern meaning, such as Oxford Dictionaries':

The use of detailed description of a work of visual art as a literary device.

(See Ruth Webb's Ekphrasis, Imagination and Persuasion in Ancient Rhetorical Theory and Practice for a discussion of how a more general device came to be associated specifically with art criticism.)

The Latin phrases look less likely to me, partly because I think they are similar enough to English words that you would probably remember them that way, and partly because they seem to be less commonly used in this specialized way. And sub oculos subiectio is not a single word.

Of all of these terms, hypotyposis seems most likely, as it is common enough to be included in various mainstream dictionaries with approximately the correct definition. One divergence from your description for any of these terms, however, is that they do not focus on unnecessary details, but rather consider vivid language to be useful and desirable.

Solution 5:

expatiate, from Dictionary.com

to enlarge in discourse or writing; be copious in description or discussion

Example: He expatiated endlessly on the theme of the joys of parenthood.

The word the OP is trying to remember may be expatiation, which could logically make sense for a climbing route that was the opposite of direct.

Embroider, from Dictionary.com

to adorn or embellish rhetorically, especially with ornate language or fictitious details: He embroidered the account of the shipwreck to hold his listeners' interest. (Emphasis added.)