Where does “nastarać” come from?

nastarać (Polish) comes from Polish na-, from Old Polish na-, from Proto-Slavic na- — on.

Ancestry of “nastarać”, step by step

StepLanguageWordMeaning
1Polishna-added to verbs to make them perfective
2Old Polishna-added to verbs to make them perfective
3Proto-Slavicna-on
Every word from Proto-Slavic na- →Every word from Polish na- →Every word from Old Polish na- →
nastarać — Etymology, Origin & Word History | Etymology Explorer