Priscian Syllabification: (Pri·scian)Pronunciation: /ˈpriSH(ē)ən/Definition of Priscian (6th century ad), Byzantine grammarian; full name Priscianus Caesariensis. His Grammatical Institutions became one of the standard Latin grammatical works in the Middle Ages. Priscian in other Oxford dictionaries Definition of Priscian in the British & World English dictionary