Priscian (Priscianus Caesariensis) (prĬsh´ən), fl. 500, Latin grammarian, b. Caesarea in Mauretania. Priscian taught grammar at Constantinople. His Commentarii grammatici, in 18 books, was long a standard text, and it was the basis of the work of Rabanus Maurus in the Middle Ages. Other extant writings of Priscian are a textbook on 12 lines of the Aeneid, a treatise on accents, a study of the meters of Terence, a treatise on symbols of weights and measures, and a work on the declensions of nouns.