Welsh cefn

← Breton kein (cognate)

← Gaulish Cebenna (cognate)

← Proto-Celtic *kebno- (inherited)

← French - (cognate)

← Cornish keyn (cognate)

← Middle Welsh keuen (inherited)

→ English Cefn (derived)

→ Breton kein (cognate)

→ Welsh cefnfor (affix)

→ Welsh cefnog (affix)