Where does “бүрәнә” come from?

бүрәнә (Bashkir) comes from Russian бревно́, from Old East Slavic бьрьвьно, from Proto-Slavic bьrvьno.

бүрәнә (Bashkir): log, beam

Definitions

Step	Language	Word	Meaning
1	Russian	бревно́	log, beam
2	Old East Slavic	бьрьвьно	—
3	Proto-Slavic	bьrvьno	—

бүрәнә — Etymology, Origin & Word History | Etymology Explorer