Dalmatic. A vestment in the shape of a tunic, worn by the deacon at a high celebration of the Holy Communion.
Deacon. The lowest of the three Orders of the sacred ministry.
Deaconess. A woman set apart for certain holy functions.
Dean. The dignitary in charge of a cathedral. The dean and chapter are the governing body of a cathedral.
Decalogue. The Ten Commandments.
Decani. The south side of the choir : the dean's side
Deist. A believer in God who rejects revelation.
Dimiasory Letters. An authorization by one bishop to another ; generally to ordain a candidate for Holy Orders.
Diocese. The district ruled over by a bishop, who is sometimes called the diocesan.
Dispensation. A licence granted by a bishop or a priest remitting a rule under certain circum-stances (e.g. fasting Communion).
Dogma. When applied to Christianity is an article of the Christian Faith ; any truth laid down by authority.
Dominican. An order of friars founded by S. Dom-inic in 1215. Black Friars.
Dorsal, Dossal. A hanging at the back of an altar.
Doxology. An ascription of praise to the ever-blessed Trinity.