Macaronic language uses a mixture of languages, particularly bilingual puns or situations in which the languages are otherwise used in the same context (rather than simply discrete segments of a text being in different languages). Hybrid words are effectively "internally macaronic." In spoken language, code-switching is using more than one language or dialect within the same conversation.
Macaronic Latin in particular is a jumbled jargon made up of vernacular words given Latin endings or of Latin words mixed with the vernacular in a pastiche (compare dog Latin).
The word macaronic comes from the New Latin macaronicus which is from the Italian maccarone ("dumpling," regarded as coarse peasant fare). It is generally derogatory and used when the mixing of languages has a humorous or satirical intent or effect but is sometimes applied to more serious mixed-language literature.