EBDOMARIUS, in ecclesiastical writers, an officers formerly appointed weekly to superintend the performance of divine service in cathedrals, and prescribe the duties of each person attending in the choir, as to reading, singing, praying, &c. To this purpose the ebdomary, at the beginning of his week, drew up in form a bill or writing of the respective persons, and their several offices, called tabula, and the persons there entered were styled intabulati.