Loanwords
The lexical stock of Proto-Slavic also includes a number of loanwords from the languages of various tribes and peoples that the Proto-Slavic speakers came into contact with. These include mostly Indo-European speakers, chiefly Germanic (Gothic and Old High German), speakers of Vulgar Latin or some early Romance dialects, Middle Greek and, to a much lesser extent, Eastern Iranian (mostly pertaining to religious sphere) and Celtic.
Many terms of Greco-Roman cultural provenience have been diffused into Slavic by Gothic mediation, and analysis has shown that Germanic borrowings into Slavic show at least 4 distinct chronological strata, and must have entered Proto-Slavic in a long period.
Of non-Indo-European languages possible connections have been made to various Turkic and Avar, but their reconstruction is very unreliable due to the scarcity of the evidence and the relatively late attestation of both Slavic and Turkic languages.
Older literature, as well as some older etymological dictionaries, often posit some alleged Eastern Iranian or Celtic source of all Slavic etymons with unclear etymologies, which in reality have very little linguistic support. Dispute on them ranges from all-inclusive to all-denial.
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