Where does “Бистрец” come from?

Бистрец (Bulgarian) comes from Church Slavonic бꙑстръ, from Proto-Slavic bystrъ, from Proto-Indo-European bʰūsro-.

Ancestry of “Бистрец”, step by step

StepLanguageWordMeaning
1Church Slavonicбꙑстръ—
2Proto-Slavicbystrъquick; penetrating, transparent
3Proto-Indo-Europeanbʰūsro-—
Every word from Proto-Indo-European bʰūsro- →Every word from Proto-Slavic bystrъ →Every word from Church Slavonic бꙑстръ →
Бистрец — Etymology, Origin & Word History | Etymology Explorer