Busman's Vocabulary

When a character in a certain profession isn't on the job, he's going to still use jargon from that profession, supposedly to let us know what he does for a living. Mafia guys will use "whacked" and the like, chefs will use culinary language, and so forth.

Contrast with Spy Speak.

Anime & Manga

 * Sanji of One Piece frequently uses allusions to food when he's calling his attacks. This is more obvious in the English dub, but the Japanese has a few food phrases too.
 * In the Viz translation of the manga, people tend to use pirate slang like "swabbie" fairly often.
 * Tyranno in the English dub of Yu-Gi-Oh! GX refers to his friends by army ranks, the school as a base of operations, and his dorm room as HQ. He also uses military slang at every opportunity. (In the original Japanese, he was a dinosaur-themed duelist with a Verbal Tic).
 * In the Keroro Gunso manga (at least in the English version), Keroro refers to Aki Hinata as "General Mom" frequently in early chapters.
 * In Ranma One Half, professional chef Ukyo Kuonji uses -- in the English version -- "sugar", "honey", and other food names as intimacy markers. Not a very noticeable trait, but the fact remains that she (almost) never used "dear" or other such markers.
 * In Portuguese, she used "Você tá frito comigo" once - this would literally mean "You're fried with (by fighting against) me". "You're toast!" would be a more natural (thus better) translation, though.
 * Dr. Minoru Kamiya has a penchant for this in Yu Yu Hakusho - In English, he says "Pronounced dead!" when attacking Yusuke from behind. In Portuguese, during the fight with Yusuke, he says "Não vou usar nenhum instrumento para te fazer uma autópsia!" - In English, "I will use no instruments to dissect you!".

Comics

 * Deadpool supporting character Fenway managed to work a baseball metaphor into practically every sentence he spoke.
 * Batman villains the Trigger Twins talk almost exclusively like characters from a Western movie.

Literature

 * This is Older Than Radio, as it dates back at least to Dickens' character, Mr. Lilyvick, in Nicholas Nickleby, a water-rate collector who uses references to pipes, taps etc. in his "normal" conversation.
 * Siuan Sanche in The Wheel of Time grew up a fisherwoman before becoming Aes Sedai, so she always uses fishing jargon and metaphors.
 * In The Fifth Elephant, we're told that Commander Vimes studies geography as though it were a crime scene ("Would you recognise that glacier if you saw it again?") Mostly though, he talks to people as though he was conducting an investigation because he always is.

Live Action TV

 * Near the end of an episode of The Sopranos, Tony tells a guy that a job might involve "getting messy. Real wet work." The FBI agents listening prick up their ears, only to realize a few seconds later he's asking someone to fix his burst water heater.
 * In an episode of The Wire, a gangbanger talks on the phone about "capping his dawg's ass". The police bring him in on murder charges, only to realize that he was talking about putting down an actual dog.
 * In Spin City, after it's revealed that one of the mayor's associates is, in fact, a mafioso, he mentions that he first suspected something when said associate invited the mayor to go fishing with, "Let's go whack some fish."
 * In Season 19 of The Amazing Race, former NFL player Marcus could always be counted on to pull out a football metaphor.
 * In the first episode of The Troop, a student's vocational test suggested he'd become an accountant. The student used accounting terms while voicing his objections to this.

Pro Wrestling

 * Practically every example in Wrestling Doesn't Pay uses this.

Video Games

 * Nate Logan from the SSX series, a cornfed ranch hand from Colorado, often says things like "Durn horse threw a shoe!" after a wipeout.

Web Animation
"Coach Z: Well, Homestar, I'll tell ya. Buying a Decemberween present for Strong Bad is like a great sports play.
 * Prior to his Flanderization into creepiness incarnate, Coach Z from Homestar Runner would overuse sports metaphors to the point that other characters started calling him out on it. From "The Best Decemberween Ever":

Homestar: Let me guess. I can't just rush into the score zone.

Coach Z: Hey, that's right!

Homestar: Coach! That's your answer for everything!"

"Homestar: Hey, yeah, melonade! We haven't talked about that in a while! And maybe we can eat some marshmellows, too!
 * Later inverted in "No Hands On Deck!" Bubs suggests that once Homestar's deck is complete, they can hang out on it drinking melonade.

Bubs: And I like to dance!"

Web Comics

 * Pick an Xkcd strip. If it's not part of the joke, odds are Randall is doing it without fully realizing.

Western Animation
"Legs: I thought you meant *gcck* hot-sync it. You know how it is with us, everything means kill."
 * The Mafia men of The Simpsons embody this trope. Fat Tony went so far as to say his wife was "whacked by natural causes". There was also a subversion in the same episode, as Tony asked Legs to "hot-sync" his PalmPilot, and Legs thought he meant to shoot it.

"Hermes: Requisition me a beat!"
 * And the Sea Captain puts everything into nautical terms.
 * Hermes Conrad of Futurama infuses his everyday language with references to bureaucracy. He also throws in semi-fabricated Jamaican idioms.


 * This is rather endemic in Wakfu. Amalia uses metaphors and expressions based on plants all the time (later episodes show us that most Sadida are doing this). Likewise, Ruel's speech often alludes to money or wealth. Minor characters are also on it; Xav the Baker and his father Ratafouine are constantly referencing bread and baking. Even Nox isn't above making a few clocks or time-related quips.
 * Tom Tucker in Family Guy still speaks like a news reporter even while not reporting the news.

Real Life

 * One of the main reasons Tropes Will Ruin Your Life.
 * And it's (probably) not even your job…
 * Engineers are known to use highly technical jargon and verbiage outside of their work environment.
 * Anytime people from the same profession get together (even if they are retired), they're going to talk shop. Listening to such conversations can be an education in itself.
 * Talking shop with someone not in your profession can also be quite illuminating, as you struggle to find ways to describe terms that, to you, are self describing in and of themselves.
 * Very true in the military. It's not the bathroom, it's the "latrine" or "head." It's not the floor, it's the "deck."
 * You know the old saying "Swear like a sailor"? It's completely true. Some retired Navy personnel retain and use some very, ah, colorful and inventive profanities when injured, angry, or frustrated.