"Dionysius" (), deriving from the name of the Thracian god Dionysus, was exceedingly common, and many ancient people, famous and otherwise, bore it. It remains a common name today in the form Dennis (Denys, Denis, Denise). The modern Greek form of the name is "Dionysios" or "Dionysis". The Spanish form of the name is "Dionisio". The Italian form of the name is "Dionigi".
The Italian last name, Dionisi is also derived from the name Dionysius, and Dionysus. "Dionysius" was the episcopal title of the primates of Malankara Orthodox Syrian Church/Malankara Church (founded by Apostle Thomas in India) from 1765 until amalgamating that title with the Catholicos of the East in 1934.More Dionysius on Wikipedia.