Irish abhainn

← Proto-Celtic *abū (inherited)

← Welsh afon (cognate)

← Irish (mention)

← Irish abha (mention)

← Proto-Indo-European *h₂ep- (root)

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

← Old Irish aub (inherited)

→ Irish fo-abhainn (affix)

→ Irish aibhneach (affix)

→ Irish abhantrach (mention)

→ Irish aibhneoir (mention)