Etymology tree Proto-Indo-European *upó Proto-Italic *supo Latin sub Latin sub-der. English sub- Proto-Indo-European *(s)ker-? Proto-Indo-European *(s)kreybʰ- Proto-Indo-European *(s)kréybʰeti Proto-Italic *skreiβō Latin scrībō Latin scrīptum Old French escritbor. Middle English scrit English script English subscript From sub- + script.