According to the Oxford English Dictionary, the word syllabus derives from modern Latin syllabus "list", in turn from a misreading of the Greek σίττυβας sittybas "parchment label, table of contents", which first occurred in a 15th-century print of Cicero's letters to Atticus [REF].
Because the word syllabus is formed in Latin by mistake, the Latinate plural form syllabi might be considered a hypercorrection [REF].