Welsh afon

← Proto-Brythonic *aβon (inherited)

← Proto-Celtic *abū (inherited)

← Proto-Indo-European *h₂ep- (root)

← Proto-Indo-European *h₂ep-h₃ōn- (inherited)

← Proto-Indo-European *h₂ep- (mention)

→ English Avon (cognate)

→ English Irving (mention)

→ English Irvine (mention)

→ Welsh afanc (link)

→ Welsh afonydd (affix)

→ Welsh afonfarch (affix)

→ Irish abhainn (cognate)

→ Scottish Gaelic abhainn (cognate)

→ Manx awin (cognate)

→ Old Irish aub (cognate)