Late 17th century; earliest use found in Ralph Cudworth (1617–1688), philosopher and theologian. From post-classical Latin polyonymos, polyonymus having many names or its etymon ancient Greek πολυώνυμος having many names, (of divinities) worshipped under many names (from πολυ- + -ώνυμος, combining form of ancient Greek (Doric and Aeolic) ὄνυμα (ancient Greek (Attic) ὄνομα) name: see onomato-) + -ous; compare anonymous.