A pun (also known as a pune, or a play on words) is a form of word play where a word with more than one meaning is exploited to make a joke or Riddle based on this double meaning. This can also take the form of substituting one word for a different, similarly sounding word. Usually done for humorous effect.
The problem with puns is that they are the lowest form of humor, (although poetry is verse), and often are not very punny, at least in English - at best, they're So Bad, It's Good. On the other hand, languages such as Chinese or Japanese, where words can be chosen for sound, character, or meaning, allow for puns of incredible complexity, working on multiple levels, and they are often viewed as an art form.
The stigma against puns in the English language is a contemporary attitude. Within historic fiction, esteemed authors pun freely including in situations that modern tastes would regard as most inappropriate. In A Christmas Carol, Charles Dickens has Ebenezer Scrooge tell the ghost of Jacob Marley "There's more of gravy than of grave about you," and Shakespeare uses a similar pun in Romeo and Juliet where Mercutio is fatally wounded (3.1.94-95) yet plays on the different noun and adjectival meanings of grave with "Ask for me tomorrow, and you shall find me a grave man." Even prim and proper Jane Austen gives Mary Crawford the line, "Certainly, my home at my uncles brought me acquainted with a circle of admirals. Of Rears and Vices, I saw enough," in Mansfield Park, leaving later generations of readers wondering whether Crawford is talking about different ranks of admirals or something else. Each of those examples reveals something within the larger context of the work: Scrooge puns when seeing the first ghost because he thinks the apparition is a hallucination caused by a bad meal, Mercutio is upbeat and witty concealing the seriousness of his wounds, and Mary Crawford's speech foreshadows that her wealth and connections have not really made her genteel.
Shakespeare puns so frequently that the original version of the "disco tent" meme illustrating this page ends in a different pun: "Now is the winter of our discontent made glorious summer by this sun of York." Richard III was the last of the Yorkist kings during the English Wars of the Roses, so that plays on the homophone sun/son of the house of York.
For trope names that are puns go to Just for Pun. For tropes that are pun names of other tropes, you want Snowclones.
- Accent Depundent: A work uses a pun that works better when said in a particular accent.
- Accidental Pun: A person says something that can be construed as a pun without their intention.
- Double Entendre: An innocuous phrase that can be reinterpreted for a more taboo or proactive message.
- Feghoot: An entire story meant to lead up to one joke, usually a pun.
- Flintstone Theming: Everything has a Punny Name in line with the themes of the media.
- Fun with Homophones: Wordplay utilizing two or more words or of identical pronunciation.
- Goroawase Number: Arabic numerals are used in Japanese in place of kanji homophonous with the numbers' pronunciations.
- Uranus Is Showing: Homophony of the name of the planet seventh distal to the Earth's sun and a phrase stating the possession of a digestive tract's terminating point by a second person.
- Hurricane of Puns: Rapid-Fire Comedy specializing in the delivery of puns.
- Pungeon Master: The summoner of the Hurricane of Puns.
- Just for Pun: TV Tropes will ruin your lines, Just for Fun.
- Lame Pun Reaction: Reception to a pun is met with indifference or contempt.
- Multiple Reference Pun: A pun is given congruent meanings due to numerous reasons.
- Pun-Based Creature: Creatures based on literal interpretations of puns and wordplay.
- Pun-Based Title: A pun is incorporated into the title of a work
- Epunymous Title: A pun about a work's eponymous character(s) is incorporated into the title.
- Parallel Porn Titles: A pornographic work has a title spoofing that of a non-pornographic work.
- Punny Headlines: Puns incorporated into a news headline.
- Punny Name: A character's name (some or its entirety) is a pun.
- "Miss X" Pun: A pun based on an honorific (ex. miss, sir) followed by a name that when said sounds like a word with a homophonous prefix.
- Quip to Black: A snappy, One-Liner comment just before the commercial break or opening sequence.
- Russian Reversal: A rephrased description in which the subject and object of the original clause are reversed. The technical term is a "Transpositional Pun".
- Stealth Pun: An extremely subtle joke (typically a pun) that is not lampshaded in the work to any extent.
- Subverted Punchline: An obvious joke is teased... and something else is substituted.
- Tom Swifty: A punny adverb when attributing a quotation, based on the content of the quotation.
- Visual Pun: A play on words in the form of an image.
- What's a Henway?: A prank that involves making a Perfectly Cromulent Word and getting someone to say "What's <word>?", similar to a knock-knock joke.
- Who's on First?: Names for things and people are mistaken for common nouns and verbs (and vice versa.)
- Duck!: The exclamation of "Duck!" is confused between the word's usages as a verb and as a noun. Rarely done with other animals/verbs.
- Owls Ask "Who?": An animal, due to its species' signature vocalization, seems to be asking a question.
- World of Pun: A work that is full of puns.
- WPUN: Pun-based radio station callsigns.