In-joke in the context of "Pun"

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.