Abstract: The subject of this research is the nature of national specificity manifestation of the lacunae belonging to different parts of speech. The goal is to describe the thematic groups of Russian-English verbal, substantive and attributive lacunae relating to the military sphere. The system of formalized indexes is used to elucidate the national peculiarity. The novelty of this research consists in revealing and testing new formalized parameters within the groups of lacunae that have not been studied from such perspective. In the course of the research, the following methods were employed: the continuous sampling method from a lexicographical source, the quantitative analysis method, comparative analysis and comparative-parametric method of linguistic research. The theoretical importance of the research is defined by the fact that methods of comparative description received further amplification. The indexes are used to determine quantitative characteristics of national peculiarity. The results obtained can be utilized in practice of teaching professionally oriented translation, comparative typology of the Russian and English languages, and be used for further inter and intra-linguistic research. Through the prism of the indexes, conclusion about the degree of the groups’ national specificity is drawn.