Where does “Sylwiusz” come from?

Sylwiusz (Polish) comes from Latin Silvius, from Latin silva, from Proto-Indo-European sēl- — to calm, quiet, be favourable.

Ancestry of “Sylwiusz”, step by step

StepLanguageWordMeaning
1LatinSilvius—
2Latinsilvawood, forest; orchard, grove
3Proto-Indo-Europeansēl-to calm, quiet, be favourable
Every word from Proto-Indo-European sēl- →Every word from Latin silva →Every word from Latin Silvius →