This article considers the lexical layer of the language, the study of which contributes to a more in-depth understanding of the culture, life, traditions of the people. Outdated vocabulary, repre-sented by historicisms and archaisms, is one of the under-explored layers of vocabulary and is the most mobile level of language in which various changes constantly occur. The reasons for archa-ization can be different, i.e. they can be associated with social transformations in the life of socie-ty, and can also be because of linguistic laws. The article attempted to lexical semantic classifica-tion of outdated words found in the texts of the Karachay-Balkarian heroic epic “Narts.” The re-sults obtained showed that outdated words of the Karachay-Balkarian language can be combined into the following thematic groups depending on their belonging to certain spheres of life: mili-tary terminology, class position, human activity, objects and phenomena of nature, names of weight measure, distance, etc. It should be noted that in the texts of the Nart epic, in addition to outdated substantive vocabulary, there are adjectives and verbs. It should also be noted that, in ep-ic texts, lexical archaisms prevail over semantic ones.