Etymology tree Latin dubō Proto-Indo-European *-tós Proto-Italic *-tos Latin -tus Proto-Indo-European *-h₂ Proto-Indo-European *-éh₂ Proto-Indo-European *-yéti Proto-Indo-European *-eh₂yéti Proto-Italic *-āō Latin -ō Latin -tō Latin -itō Latin dubitō Latin -bundus Latin dubitābundus From dubitō (“waver, doubt”) + -bundus.