Situated at the intersection of various academic disciplines, multilingualisim has attracted the attention of several categories of researchers specializing in studying the ancient Roman world, including historians, philologists, linguists, literary scholars, epigraphists, and papyrologists. While Greek-Latin bilingualism, which constitutes the most remarkable aspect of ancient multilingualism, has been the subject of landmark, comprehensive studies, and although it is now well described and theorized, there still is not a single study on the relationships between Latin and the other languages of the Empire that takes into account the various aspects of the question and synthesizes the data that have emerged from these disciplines. Looking closely at the lexicon used by the Romans to describe the phenomenon of multilingualism and linguistic interference also shows that, contrary to a commonly held opinion, not only did the Romans not demonstrate an “incuriosity” regarding foreign languages, but they even developed their own linguistic reflection on the subject.