This article comprehends the materials of the dictionary “M. V. Lomonosov’s Rhetoric” which was prepared by the team of the department “The Dictionary of the Language of M. V. Lomonosov” of the Institute for Linguistic Studies (Russian Academy of Sciences) in collaboration with the seminar “Russian XVIIIth Century” (St Petersburg State University) and published in St Petersburg in 2017. The paper focuses on the comparison of the terminology of tropes and figures in the rhetorical treatises by M. Lomonosov (“Brief Guide to Rhetoric” and “Brief Guide to Eloquence”) and in the East Slavonic rhetorical treatises of the 17th century: “Rhetoric” of 1620, “Rhetoric” by Sofroniy Lihud, translated from Greek by Kozma Afonoiversky (1698), “Rhetoric” by Mikhail Usachev (1699) and “Rhetorical hand” of Stefan Yavorsky, translated from Latin by Fedor Polikarpov (1705). We show that, unlike his predecessors, Lomonosov provides strict differentiation between Greek borrowings and lexemes which are Russian by origin: all terms of the section “Tropes” are Greek, and all terms of the section “Figures” are Russian. The uniqueness of Lomonosov’s “Brief Guide to Eloquence” lies in the fact that it tends to lack terminological redundancy and synonymy which was common in Russian rhetorical treaties of the 17th centuries. We analyze the oscillations that Lomonosov experienced during the nomination of tropes and figures. Сhanging the terminology of the “Figures” section, Lomonosov replaced Greek terms by Russian, replaced loan translations by new terms that better explain the concept, sought to use a single word-formation model and to abandon tautology. It demonstrates the diversity of Lomonosov’s creative approach to the terminological heritage of his predecessors: in some cases, he “borrows” existing terms, in others he invents terms of his own or varies those that already exist, yet in others, first using a new term he abandons it and opts for the original term.