The present article analyses English and Russian lexemes denoting core legal professions and positions and emphasizes the problem of their translation equivalency. The aim of the paper is to show that although terms are named among those limited groups of lexemes which are context-independent and characterized by a single meaning, they can also be poly-semantic and even enantiosemic, i.e. contain opposite meanings within a single word form which can be specified only in the context, including the cultural context. This fact poses serious problems in translation. The authors limited the research to the lexemes denoting core legal professions of the semantic groups of defense and prosecution. The data was taken from dictionaries, legal texts as well as Russian and British National Corpora. Drawing on equivalence theory, descriptive theory, distributive theory and discourse analysis the study explores the semantics of the terms, analyses their distinctive features, and marks their semantic, functional and stylistic differences. It implements definitive, distributive, contextual, and contrastive analyses. This approach enabled the authors to specify semantics of the English and Russian terms, their functional and cultural differences and suggest some practical recommendations for their translation from the source language into the target language. The results of the study can be applied in the theory and practice of translation and in teaching Professional English and Russian to Law students.