I started to reread Dashiel Hammett’s Maltese Falcon. For those that don’t know Hammett had a great deal of influence on the detective story. Sure, Edgar Allen Poe and Sir Arthur Conan Doyle were there first, but Hammett did more to influence the form of the modern detective story. Hammett worked as a private detective for a short period. When his detective stories became popular, his terminology was taken as a true representation of how cops and crooks spoke. Many of his terms were adopted by other writers and through repetition have become accepted terms. Mystery writers from Raymond Chandler to Robert Crais and all the mystery writers in between owe a debt to Dashiel Hammett.
Earl Stanley Gardner investigated Hammet’s prose and penned an article about his use of language. At the link: https://www.miskatonic.org/gooseberry.html
It turns out that shamus has no basis, in fact, as a term for a private investigator. Try telling that to legions of mystery writers that followed. There is even a movie named Shamus.
Legend has it that Hammet’s editor objected to the term gooseberry lay, an archaic term for a thief. The gooseberry lay refers to a thief that steals clothes from a clothesline. Hammet didn’t invent it. Possibly in retaliation, Hammet was able to slip the term gunsel into the text. Everybody knows that gunsel is a term for a gunman/bodyguard. Except it isn’t. Gardner is rather circumspect in his definition of the term. The word is Yiddish in origin and means a young man who engages in homosexual acts with an older man. Gunman or boytoy, either definition fits Hammet’s description of Wilma, Gutman’s bodyguard in The Maltese Falcon.
Hammet is a piker when it comes to creating new terms to suit his narrative. J.R.R. Tolkien didn’t limit himself to single terms. He created new languages supplemented by alphabets and grammatical rules. Anybody who has ever read Joseph Wambaugh knows that his choir practice and the bishop’s choir practice are not the same. Another example can be found in the spy lingo created by John LeCarre. His world is populated with pavement artists, lamplighters and moles.
The tradition continues. Unfortunately, it is no longer limited to fiction. Some examples:
Whether or not a term gains acceptance is determined by the individual. Some have tried and failed. Take, for example, Ambrose Bierce, forever destined to wander the Southwest border with Mexico.