The study of religious language in modern linguistics has opened up opportunities for various kinds of research. The object of the study is the religious vocabulary as an integral part of the religious language, which can function in various ways. Russian and Polish Christian eortonyms translation, single - and bilingual general and specialized dictionaries of Polish and Russian religious vocabulary, and works on religious language were used as the research material. Attention is drawn to the need for further research not only of the “Orthodox version” of Polish, but also of the practically unexplored “Catholic version” of the Russian religious language, since the meanings of eortonyms are directly dependent on these variants. In the course of the analysis of the material under study, translations of words with the meaning “Christian holiday” with varying degrees of accuracy and the resulting features of their lexicographic description were noted. In the case where there were complete correspondences of the equivalents, their translation and lexicographic description did not raise difficulties. In cases of partial coincidence and mismatch of the names of holidays, the reasons affecting the quality of their translation were noted, such as the confessional affiliation of the authors of dictionaries and their users; various calendars of Christian denominations, dates and traditions of celebration. Therefore, in the analyzed Polish-Russian translations of Catholic eortonyms, there are cases of using Orthodox vocabulary, and in the Russian-Polish translations of Orthodox eortonyms – Catholic. Typical translation techniques were also identified: explication, in the case of translation of non-equivalent words, adaptation and othering.