Where does “penysgawn” come from?

penysgawn (Welsh) comes from Welsh pen, from Proto-Brythonic penn, from Proto-Celtic kʷennom — head.

Ancestry of “penysgawn”, step by step

penysgawn traces back through two separate lines of ancestry.

via Welsh pen

StepLanguageWordMeaning
1Welshpenhead; chief; top, apex
2Proto-Brythonicpennhead
3Proto-Celtickʷennomhead

via Welsh ysgawn

StepLanguageWordMeaning
1Welshysgawn—
2Middle Welshysgavyn—
3Proto-Celtic*skamoslight (not heavy)
Every word from Proto-Celtic kʷennom →Every word from Proto-Brythonic penn →Every word from Welsh pen →