Etymology tree Proto-Indo-European *(H)reh₁-der. Proto-Indo-European *(H)reh₁ís Proto-Italic *reis Latin rēs Proto-Italic *poplosder. Old Latin poplusder. Old Latin poplicus Latin pūblicus Latin pūblica Latin rēspūblicalbor. Portuguese república Latin foedus, foederis Proto-Indo-European *-h₂ Proto-Indo-European *-éh₂ Proto-Indo-European *-yéti Proto-Indo-European *-eh₂yéti Proto-Italic *-āō…