Infectious diseases are considered to be one of the main threats to the health of the people today, as well as a significant burden on health care and society as a whole. The latter is due to the fact that most of these diseases cause temporary or permanent disability, require huge financial costs for prevention, treatment, rehabilitation (and some of them lead to lifelong therapy) and negatively affect the quality and duration of life and cause premature death. In general, the concept of “socially significant diseases” has existed since the nineteenth century, a period of rapid economic development. Unfortunately, the current course of events with the global pandemic has aroused a great interest in the medical field of “Infectology”. Our linguistic research concerns the structural and semantic analysis of the terminological sphere of this branch of medicine. The real functioning of terms in modern Ukrainian publications on medicine testifies to the incompleteness of the medical terminology normalization process, in particular, numerous violations of lexical and morphological norms. It is clear that the standardization of the medical terminology directly depends on the solution of a number of problems: coordination of national and international components, elimination of synonymy, variability, violations of lexical, morphological and syntactic norms of the Ukrainian language. The most important aspect is the development of a single concept of term formation, which uses the experience and positive accomplishments of scientists of different generations. Ensuring the linguistic normativeness of terms should take place at all the levels – both conceptual and linguistic – phonetic, orthoepic, orthographic, lexical and semantic, word-forming, morphological and syntactic. Thus, lexical and semantic study of the linguistic features of the formation and development of professional discourse is of great interest. The productivity of adjectival lexical units of the medical terminological branch of “Infectology” were analyzed in the following article. The lexical and semantic features of their construction are characterized and the attention is focused on the main word-forming types of complex adjective phrases of the terminological space of the corresponding branch. The issue of thematic grouping of terminological adjective phrases depending on the semantics of the core term-component is raised and it is found that the functioning of such terminological compounds demonstrates word-forming processes that contribute to the unification of professional language.