prologetic

Probably either from the Latin prologēticus or formed in English as prologue + -etic, in both cases resembling a hypothetical Ancient Greek etymon of the form *προλογητικός (prologētikós), from πρόλογος (prólogos, “prologue”) + -ητικός (-ētikós, “-etic”), a formation akin to the extant words ἀναλογητικός (analogētikós, “analogetic”) (from ἀνάλογος (análogos), whence analogue), ἀπολογητικός (apologētikós, “apologetic”) (from ἀπόλογος (apólogos), whence apologue), and ὁμολογητικός (homologētikós, “homologetic”) (from ὁμόλογος (homólogos), whence homologue).

来源：wiktionary