Where does “ośmiolatka” come from?

ośmiolatka (Polish) comes from Polish ośmiolatek, from Polish osiem, from Old Polish ośm, from Proto-Slavic osmь, from Proto-Balto-Slavic aśmas, from Proto-Indo-European oḱtṓwos, from Proto-Indo-European oḱtṓw, from Proto-Indo-European aḱ- — sharp, pointed; sharp, pointed, edgy; sharp,...

Ancestry of “ośmiolatka”, step by step

StepLanguageWordMeaning
1Polishośmiolatekeight-year-old
2Polishosiemeight
3Old Polishośmeight
4Proto-Slavicosmьeight
5Proto-Balto-Slavicaśmas
6Proto-Indo-Europeanoḱtṓwoseighth
7Proto-Indo-Europeanoḱtṓweight
8Proto-Indo-Europeanaḱ-sharp, pointed; sharp, pointed, edgy; sharp,...
Every word from Proto-Indo-European aḱ-Every word from Proto-Indo-European oḱtṓwEvery word from Proto-Indo-European oḱtṓwos