Early 17th century; earliest use found in John Taylor (1578–1653), poet. From classical Latin Priāpēus of or belonging to Priapus, designating a metre (from Hellenistic Greek Πριάπειος of or belonging to Priapus, usually designating a metre from Πρίαπος + -ειος, suffix forming adjectives) + -an. Compare French priapéen belonging to the cult of Priapus, designating a metre.