Based on the material from Slavic languages, the article presents a corpus analysis of
adjectives describing the physical quality of “being clean or pure,” as well as the related situa-
tions of “being transparent/ clear” (as regards the sky). Slavic data are viewed from a broader
typological perspective, which makes it possible to assess the degree of diversity within the
Slavic systems. Although existing studies on the intragenetic typology of lexicon reveal sig-
nificant differences between related languages, Slavic systems in the ‘clean/pure’ domain are
rather similar. Nevertheless, the specific features of individual systems allow us to define the
mechanisms that result in lexical divergence of related languages.