Proto-Slavic *bykъ

→ Belarusian бык (inherited)

→ Bulgarian бик (inherited)

→ Czech býk (inherited)

→ Old Church Slavonic бꙑкъ (inherited)

→ Lower Sorbian byk (inherited)

→ Macedonian бик (inherited)

→ Polish byk (inherited)

→ Russian бык (inherited)

→ Serbo-Croatian bik (inherited)

→ Serbo-Croatian бик (inherited)

→ Slovene bik (inherited)

→ Ukrainian бик (inherited)

→ Yiddish ביק (derived)