In-joke in the context of "The Producers (musical)"

A pun, also known as a paronomasia in the context of linguistics, is a form of word play that exploits multiple meanings of a term, or of similar-sounding words, for an intended humorous or rhetorical effect. These ambiguities can arise from the intentional use of homophonic, homographic, metonymic, or figurative language. A pun differs from a malapropism in that a malapropism is an incorrect variation on a correct expression, while a pun involves expressions with multiple (correct or fairly reasonable) interpretations. Puns may be regarded as in-jokes or idiomatic constructions, especially as their usage and meaning are usually specific to a particular language or its culture.

Puns have a long history in writing. For example, the Roman playwright Plautus was famous for his puns and word games.

xkcd (sometimes styled XKCD) is a serial webcomic created in 2005 by American author Randall Munroe. The comic's tagline describes it as "a webcomic of romance, sarcasm, math, and language". Munroe states on the comic's website that the name of the comic is not an acronym but "just a word with no phonetic pronunciation".

The subject matter of the comic varies from statements on life and love to mathematical, programming, and scientific in-jokes. Some strips feature simple humor or pop-culture references. It has a cast of stick figures, and the comic occasionally features landscapes, graphs, charts, and intricate mathematical patterns such as fractals. New cartoons are added three times a week, on Mondays, Wednesdays, and Fridays, with few exceptions.