The study is devoted to identifying the patterns of formation and development of legal terminology in the key sectoral codes of Russia in comparison with the civil and criminal legislation of the states of the continental legal family, and to assessing how borrowing methods affect the quality of legal regulation and legal certainty. The aim of the work is to identify the main models of transfer and subsequent adaptation of legal concepts, as well as to evaluate the degree of their correspondence to national doctrinal approaches and judicial practice. The materials include the texts of civil and criminal codes of Russia, Germany, and France, as well as acts of higher judicial authorities and scholarly works on the theory and comparative study of law. The methodological basis includes comparative legal, formal legal, historical legal, linguistic, and systemic approaches, which make it possible to trace the evolution of terms from the moment of reception to their consolidation in the national legal system. Several stable models of borrowing have been identified, including direct inclusion of foreign terms, semantic calquing using word combinations familiar to the Russian language, and the reception of integral doctrinal constructs with subsequent development of an original conceptual framework. It is shown that the success of adaptation depends on the completeness of the transfer of the normative and doctrinal context associated with the term, as well as on the timely development of explanations by higher courts, which in fact completes the process of nationalizing the concept. It has been established that there are terms with a discrepancy between their external similarity and actual content, which creates the risk of misinterpretation, especially in cross-border legal relations. The role of legislative technique and judicial practice in overcoming terminological collisions and forming a coherent system of concepts is discussed, ensuring both compatibility with the European legal tradition and reflection of the specific features of Russian legal reality. Proposals have been formulated on the need for a more systematic analysis of vocabulary when borrowing new institutions, for a preliminary assessment of possible conflicts of meanings, and for the development of a special doctrine of legal language as an independent branch of comparative jurisprudence.