Proto-Slavic *bystrъ

→ Belarusian быстры (inherited)

→ Bulgarian бистър (inherited)

→ Czech bystrý (inherited)

→ Kashubian bëstri (inherited)

→ Old Church Slavonic бꙑстръ (inherited)

→ Macedonian бистар (inherited)

→ Polish bystry (inherited)

→ Romanian Bistra (derived)

→ Romanian Bistrița (derived)

→ Romanian Bistreț (derived)

→ Romanian Bistrețu (derived)

→ Russian быстрый (inherited)

→ Serbo-Croatian бистар (inherited)

→ Serbo-Croatian bistar (inherited)

→ Slovak bystrý (inherited)

→ Slovene bister (inherited)

→ Ukrainian бистрий (inherited)

→ Old Armenian ըմբոստ (mention)