Welsh oen

← Breton oan (cognate)

← Proto-Brythonic *oɨn (inherited)

← Proto-Celtic *owignos (inherited)

← Proto-Indo-European *h₂egʷnós (inherited)

← Old Irish úan (cognate)

→ Breton oan (cognate)

→ Welsh maharen (link)

→ Old Irish úan (cognate)