Beginning in the 17th century, during the Russian exploration of Siberia, the influence of the Russian language on the indigenous languages grew, including the Siberian Turkic languages, particularly Teleut, whose vocabulary acquired a layer of phonetically and semantically adapted Russian loanwords – non-equivalent names for Russian and European cultural realities. Dictionaries of Turkic languages by VV. Radlov and VI. Verbitsky, published in the second half of the 19th century, list approximately 70 and 50 Teleut words, respectively, labeled as loanwords from Russian; the modern Teleut-Russian dictionary by LT. Ryumina (1995) includes approximately 35 unmarked Russian lexical loans. Among these, a prominent layer of lexemes with ambiguous etymologies stands out, which may be Russian loanwords or have an earlier Turkic or Eurasian origin. The purpose of this article is to identify and compare existing etymologies of Teleut words with unclear origins (Russian borrowings, borrowings from other languages, or native). The materials include 19th-century dictionaries and modern explanatory and etymological dictionaries of Turkic and Slavic languages. Descriptive, comparative-historical, and contrastive methods were used. The semantics of 20 Teleut words – names of outbuildings, utensils, clothing, and food products – were analyzed. These words have sound and semantic parallels in Russian but, in our opinion, do not clearly represent borrowings from Russian dialects of Siberia into Teleut. Some lexemes are presumably of native Turkic origin, while others may have entered Russian and Teleut from other Eurasian languages. The theoretical and practical significance of this work lies in clarifying the origins of a number of words classified as Russian lexical loans in the Turkic languages of Siberia. In addition, the work makes a certain contribution to the study of Russian-Teleut cultural and historical intercourse in the 17th-19th centuries, as well as the general theory of language contacts.