Proto-Slavic *ostrъ

→ Belarusian востры (inherited)

→ Bulgarian остър (inherited)

→ Czech ostrý (inherited)

→ Old Church Slavonic остръ (inherited)

→ Lower Sorbian wótšy (inherited)

→ Macedonian остар (inherited)

→ Polish ostry (inherited)

→ Russian острый (inherited)

→ Serbo-Croatian oštar (inherited)

→ Serbo-Croatian оштар (inherited)

→ Serbo-Croatian oštro (inherited)

→ Slovene oster (inherited)

→ Silesian ôstry (inherited)

→ Ukrainian гострий (inherited)