Pun

[Rihanna]

A play on words, usually for a comic reception.

[Jessica]

A pun is, quite simply, a play on words. There are many types, but in general, they all utilize one word that is relevant to the subject matter at hand, but is impractical in context. If formed correctly, a pun can be humorous, and can sometimes [derail] any given conversation in itself.
Puns are common comedic tools in literature, conversation, [blogging], and all other sorts of digital and interpersonal communication. However, they are surprisingly complicated, and the concept of what comprises a pun can be confusing. Simple puns, such as humorous rhymes (i.e., guy sees a woman get decapitated in a movie Geez, she didnt need to lose her head over that.), are not unfamiliar to the average speaker, and most of us have used them since our earliest years. Complex puns, such as the use of words in actual sentence structure (for example, daughter gets her father an Icee slushie Icee what you did there!) require some degree of verbal and dictional proficiency.
Some guidelines:

It should be clearly relevant to the topic of discussion at hand, while being unnecessary (i.e, it certainly would not be the first thing you would use).

It should be fairly easy to recognize; puns often use elements of [cliche] and popular phrasing.

It should be timely. The goal is to be clever, not predictable.

A good way to understand how puns work is to ponder the place of irony in humorous context.

[Rihanna]

Wielded by anyone but a true [master], a pun is the lowest form of [humor]. However, wielded by a master, a pun is the highest, purest form of humor possible by [humans].
Puns are a dark art, much like [necromancy]. Raising the dead will get you killed. Raising a pun with your killer sense of humor will get you killed, making it a grave [mistake], even if you were dead serious.
Puns can be categorized into the following:
One Liners
Micro-Liners:
Made in only a few words, these can only be wielded by true pun masters (Think word-within-a-word)
Epics:
This is the most evil form of pun magic. An epic is when someone finds a basic enough pun, then creates an incredibly detailed background for it, taking as much as hours to read, then ending it with the most basic one-liner or even micro-liner. The key to these is to find a pun that is the easiest to set up, then just drag it out as intricately as possible to create a story that feels like it will have an incredible ending, but ends with a three-word micro-liner.
Everything else:
This ranges from creative plays on words or just idiots
WARNING:
Practice puns with a friend who does not know how to commit murder, otherwise you will be brutally disemboweled. Until you can call yourself a true master, avoid using them in public. (Shameless plug: #puns and #pungrandmasters on Kik has a lot of pun-lovers, including me, the master, who will aid you in your dark humor quests without brutally murdering you... usually)

[Becky]

1. A joke, usually a play on words involving either a homonym, or a phrase that rhymes with the original quote.
2. A very, very, VERY low form of humor, and often makes everyone within a ten mile radius sigh and pinch their eyes together.

These jokes will likely get you killed, the best case scenario is that someone laughs, simply because the joke is so bad/stupid, that said person cannot help but laugh, then tell you to get the out of the room.

[Jessica]

A noun used to represent a form of play-on-word that dwells on taking advantage of similar sounding words or different definitions/implications of a certain word or phrase, generally used for comic relief, or to express your own cleverness and distaste of others sanity. Not to be confused with [double entendre]. A well crafted pun requires both flow of pronunciation and well-layered meanings.

[Sonia]

something that should have died a long time ago