The Sanskrit word campū is usually understood to refer to a literary composition that combines prose and verse. I argue that this sense of the word was not available before the tenth century CE, and the vast majority of compositions that have been called campūs, either in premodern commentaries or in modern scholarship, were not and could not have been so called by their authors. This is true of almost the entirety of so-called “campū literature” in Kannada. The reference to campū as “a particular type of composition consisting of prose and verse” in Daṇḍin’s Mirror of Literature (ca. 700 CE) was probably not a definition, despite the fact that it has almost-universally been taken as such by the tradition of Indian poetics and modern scholarship. I propose that the campū might have originated as a subliterary comic performance, and that Daṇḍin (unknowingly) and Trivikramabhaṭṭa (knowingly) helped to establish the now- familiar sense of the word.