Informed Obscenity

A completely nonsensical word (sometimes made up, sometimes not) established as being "inappropriate".

Compare with But Not Too Evil. Related to Unusual Euphemism and Pardon My Klingon, and a sub-trope of Perfectly Cromulent Word.

Anime and Manga

 * In Hanasaku Iroha, Tsurugi Minko uses the word "horibon" (meaning "balut") as an insult towards Ohana as a replacement for the more harsh insults that she'd been using, as per Ohana's request.

Comic Books

 * In Nodwick, one issue revolves around the word "Krutz", a fictional swear word that ends up being a one-issue Berserk Button to Piffany. It even comes with its own marketing campaign!
 * Sweary Mary of Viz invents a new swearword. "Fitbin" is bot (we are informed) obscene, and also obscure enough to put on the front page of a comic.

Film
"R2-D2: (electronic beeps) C-3PO: You watch your language!"
 * From the original Star Wars:

Literature
""Are we talking," said Arthur, "about the very flat country, with all the EEC and the fog?" "What?" said the girl. "Belgium," said Arthur. "Raaaaaarrrchchchchch!" screeched the pterodactyl. "Grrruuuuurrrghhhh," agreed the seven-toed sloth. "They must be thinking of Ostend Hoverport," muttered Arthur. He turned back to the girl. "Have you ever been to Belgium in fact?" he asked brightly and she nearly hit him. "I think," she said, restraining herself, "that you should restrict that sort of remark to something artistic." "You sound as if I just said something unspeakably rude." "You did.""
 * In the Hitchhiker's series, the word Belgium, while on Earth the name of a country, is elsewhere the last vulgar expletive, properly reserved for use in Serious Screenplays.

"Don't give me any of your bowb! Get over here, you stupid bowb! What is this, "Bowb Your Buddy Week?" "Every week is Bowb Your Buddy Week." Bowbity-bowb bowb!"
 * Oddly, though, the entire gag originated in the radio series, but was added only to the US edition of the book. The prize in question in the UK version was just for the most uses of "Fuck" in a serious screenplay, and passed uncommented upon.
 * At one point in Diary of a Wimpy Kid, Manny starts calling Greg "pootie" out of the blue. Thinking it is a "little kid bad word", Greg asks their mother about it, though she is clueless and does nothing about it -- freeing Manny to use the word wherever and whenever he wants. Later, while the family is in church, Greg uses the name on Manny to get him to stop bugging him, and Manny becomes hysterical -- only then does the word become obscene in their mother's eyes.
 * In Hogfather, carolers have changed the lyrics to a song so it starts "the red rosy hen" (presumably the word used to be "cock"). The book goes on to say that the carolers often had to stand and show people where they thought the obscenity was before they would be offended by it.
 * At one point in The Mysterious Disappearance of Leon (I Mean Noel) by Ellen Raskin, Mrs. Carillon is jailed and protesters gather outside the prison. Because the signs the protesters are using were painted over and reused after a grape farmers' strike, one sign that was evidently left unfinished inadvertently reads "GRAPE MRS. CARILLON". Nearly everyone who sees the sign comes to the conclusion that "grape" means something horribly offensive, culminating in a bystander attacking the sign-holder and yelling "Grape Mrs. Carillon? Grape you!".
 * Harry Harrison's Bill the Galactic Hero introduced 'bowb' as a made-up all-purpose swear word to substitute for the rich variety of vulgarities in use by soldiers (in order to keep the book from being censored):


 * Samuel Blink And The Forbidden Forest: Stinkymudfungle!
 * Alluded to with "cagal" in Harrison's The Stainless Steel Rat Gets Drafted.
 * In one of the Oz books, in a moment of great rage, the Nome King exclaims "Hippikaloric!" The narrator helpfully notes that this "must be a dreadful word because we don't know what it means."

Live Action TV

 * The Trope Codifier is Monty Python's Flying Circus, where, after a sketch filled with naughty words, Michael Palin appears to show us a list of words that will not be tolerated on the program. After a list of (decidedly British) dirty words, the word "Semprini" appears. A woman then comes on screen and says, "Semprini?" prompting Michael to throw her out. Incidentally, the word is the last name of composer Alberto Semprini.
 * Dinosaurs had one episode in which a great controversy erupted over the word "smoo".
 * Not to mention flark, and glick.
 * A Bit of Fry and Laurie had a man on trial for public obscenities, all of them bizarre.

Music
"Banana banana banana banana terracotta banana terracotta terracotta pie!"
 * System of a Down's not particularly subtly named "Vicinity of Obscenity" uses object and visual imagery to suggest sexual and scatological themes without saying anything even remotely dirty in a literal way.

Newspaper Comics

 * In a brief arc in Bloom County, moral guardians were cracking down on the strip for the use of "inappropriate language", citing frequent uses of "the four-letter H-word, the four-letter D-word, and the fourteen-letter S-word". After heavy speculation as to what this latter word is, one of the characters announcing this can only think of "Snugglebunnies?" (the former Trope Namer).
 * In the next strip, the two remark on how somehow saying "Snugglebunnies" is bad enough to get the strip cut. Their response: "We have one thing to say to that. Snugglebunnies! Snugglebunnies! Snu-" and the strip gets cut mid-word. Interestingly, later in the strip's run, the word started showing up frequently.

Oral Tradition

 * There is a Shaggy Dog Story about a man who repeatedly gets into progressively worse trouble (culminating in a courtroom case) for uttering the phrase "blue flower", because he keeps saying it when asking people what it means and getting into trouble instead of getting an answer. The punchline involves him getting hit by a truck or something and suddenly dying just as he's about to find out. Other variants involve a boy getting kicked out of school for a similar infraction. The word/phrase varies with each telling, with examples including "two pink elephants", "purple passion", and "branchwater".

Radio

 * In Adventures in Odyssey episode "War of the Words", two kids overhear Eugene call Connie a "maladroit", which they don't understand, but like the word anyway. They proceed to call various people "millijoit" before they get in trouble. The episode ends with An Aesop about speaking respectfully, regardless of what words are used.

Webcomics

 * In Aquapunk, "cet" is the Sennan catch-all profanity and expletive.
 * A Penny Arcade strip showed Microsoft using the Precog-system from Minority Report to predict words that are ABOUT to become profanity. The word that gets pulled down is 'Ham Doctor'.
 * One Ugly Hill strip reveals that the word "wink" is used as a racial slur against one eyed monsters in the strip's universe.

Web Original

 * A Something Awful Let's Play of Quest for Glory stars a hero with the pseudonym "Nike von Slartibartfast"; when questioned, the hero explains that he chose nonsense words that most people would think sounded dirty. Douglas Adams came up with the name Slartibartfast by working backwards from a string of obscenities to come up with a name that sounded very rude but could be read over the air for the original The Hitchhiker's Guide to the Galaxy radio series.

Western Animation

 * Family Guy has something like this, where Tom Tucker mentions the "trendy new curse word -- clemen." According to the DVD commentary, Seth MacFarlane jokingly said that if "clemen" does become a real-life curse word, then the scene of Tom Tucker mentioning it will have to be censored in hindsight.
 * On Recess there was an episode where T.J. was brought to court for use of his Catch Phrase "This whomps". The judge decided that "whomps" was not dirty in and of itself, and that only a dirty-minded person would think it was.
 * In the South Park episode "It Hits The Fan", The Knights of Standards and Practices each represent a different bad word. One of these: Meekrob, the name of an actually delicious Thai dish that Cartman had earlier said he was going to start using as a swear word.
 * In The Boondocks episode, "The S-Word," the eponymous 12-letter "s" word is "spearchucker." While this is a derogatory (if somewhat antiquated) term for a black person, the fact that the school district expects people to automatically know what the "twelve letter S-word" is is what makes this an example. Of course, the entire episode is a non-stop mambo over the N-Word Privileges line.
 * An episode of SpongeBob SquarePants claims that there are thirteen dirty words, all of them represented by some sort of sound effect, the most prominently featured being a dolphin's chirp. This appears to be an odd version of Sound Effect Bleep until a moment of Lampshade Hanging at the end of the episode in which an actual car horn is mistaken for a character swearing.
 * In the Berenstain Bears, "Furball" is considered horribly offensive, as Sister found out when she and Lizzy learned it from a video Lizzy's old brother rented.