One interesting word that appears early in the story is "stir." This used to be a common slang term used by criminals for "prison." They also used "the pen," "the joint," "the slammer," "the big house," and many others.
The slang words "crack" and "cracked" appear often. They apply to a safe that is broken into by one means or another, including by explosives. Jimmy Valentine is a top professional safe-cracker.
Criminals used and still use the word "job" to refer, ironically, to a crime such as a burglary or a robbery. Jimmy's burglaries are all "jobs" in the underworld argot.
The warden uses the word "bull-pen" early in the story. This is a big cell where a number of men are confined together. Evidently these men are there only for a short term or, like Jimmy, are going to be released.
The word "collar-button" dates the story. Men used to wear detachable collars which were held in place by a simple metal "button." Ben Price lost his collar-button while grappling with Jimmy in his room ten months earlier when he arrested him for the "Springfield job."
A "four-in-hand" knot in a necktie is the simplest kind of knot to tie--but it is hard to make it look good. It usually ends up looking lopsided. Windsor knots or half-windsor knots are more popular today, but men's collars are also different and typically allow for larger knots than the old-fashioned high collars. Jimmy apparently had a talent for tying a four-in-hand which the desk clerk remarked at the hotel in Elmore, Arkansas.
Jimmy's fiancee Annabel Adams is joking when she asks him if she wouldn't make a good "drummer." That word used to be widely used to apply to traveling salesmen. Annabel is lifting Jimmy's heavy suitcase when she asks this question. He has to make up something to explain why it is so heavy.
Jimmy tells Annabel the suitcase, which is really full of steel burglar tools, is full of metal "shoe-horns." These used to be much more common when men and women wore high-top shoes, because they were very useful for getting those shoes on. The shoe stores used to give the shoe-horns away with purchases of shoes. But many people owned fancy shoe horns which were often made out of cow horns and looked like plastic.
Those are 8 interesting words found in "A Retrieved Reformation":