This article examines the lexical and grammatical features of kinship terms in the modern Uzbek language. The author identifies lacunar units—concepts that lack direct equivalents in Russian—and explains their origins, semantics, and sociocultural meanings. Special attention is given to kinship terms distinguishing paternal and maternal lines, as well as their connection to Islamic culture, inheritance, and marriage traditions. The study is based on comparative-ethymological and sociolinguistic analysis, including examples from Uzbek literary works and religious sources.