The first part of the article provides a brief overview of works reflecting the mutual interest of ethnolinguistics and etymology in which the capabilities and achievements of each other are used (articles by V.N. Toporov, O.N. Trubachev, S.M. Tolstaya, A. Loma and M. Bjeletiћ, K., O. and M. Stachowskie, H. Schuster-Šewc, books by U. Dukova, N. Hobzey, R. Dźwigoł and others). The result of this interaction in the field of mythological vocabulary shows its fruitfulness in the study of lower Slavic mythology. In the second part of the article, the etymologies of two rare Slovak demonyms are proposed. The first is the name of the local Ccentral-Slovak character grgalica / grgolica, which, based on the assessment of the mythological image, its typological features, as well as the analysis of the same root vocabulary in different Slavic languages, is proposed to be associated with the onomatopoetic verb grgať and similar. The second term – West-Slovakian Bendúš - known from the description of the young people spring game and understood by the author of information about him as a relic of a certain deity, is plausibly explained as an anthroponym derived from the root bend- ‘belly, thick’.