Proto-Slavic *gladъkъ

→ Belarusian гладкі (inherited)

→ Bulgarian гладък (inherited)

→ Czech hladký (inherited)

→ Old Church Slavonic гладъкъ (inherited)

→ Lower Sorbian gładki (inherited)

→ Upper Sorbian hładki (inherited)

→ Macedonian гладок (inherited)

→ Polish gładki (inherited)

→ Russian гладкий (inherited)

→ Serbo-Croatian gladak (inherited)

→ Serbo-Croatian гладак (inherited)

→ Slovak hladký (inherited)

→ Ukrainian гладкий (inherited)