The Deacon is the third and lowest degree of the major orders of clergy in the Orthodox Church, following the bishop and the presbyter. The word deacon (in Greek διάκονος) means server and originally it referred to a person who waited on tables.
With the blessing of the presiding priest or bishop, the deacon leads the people in the collective prayers and reads from the Holy Scriptures during the divine services. He is also responsible for the decorum of the public worship and calls the people to attention at appropriate times.
In addition, the deacon may perform other tasks related to Church life from time to time with the blessing and at the direction of his priest or bishop.
A deacon may be blessed by his bishop and parish priest to distribute the Eucharist to the faithful, either from a second chalice at a regular liturgy where a priest is serving or in connection with a typika service that is celebrated when the priest is absent. In neither case, however, does the deacon consecrate the Holy Gifts. The deacon has no ability or authority to consecrate the Holy Gifts on his own.
Rankings of deacons
Sacramentally, all deacons are equal. However, they are ranked and serve by seniority according to the date of their ordination.
Just as with bishops and presbyters, there are distinctions of administrative rank among deacons. A senior deacon of a cathedral or principal church may be awarded the title protodeacon and claim precedence when serving with other deacons. The chief deacon who is attached to the person of a bishop is called an archdeacon. A deacon who is also a monastic is called a hierodeacon.
For formal occasions (for example, in the heading of a letter or when introducing a speaker), one would politely address or refer to a deacon as "The Rev. Deacon [John Smith]." Deacon is often abbreviated Dcn. or Dn.
In informal settings, for example, in normal conversation, it is appropriate to simply refer to a deacon as "Deacon [John]." Note that in some traditions, however, it is common to refer to deacons as "Father"—for instance, "Father Deacon [John]" or even "Father [John]."
Deacons cannot bless, so it is inappropriate to ask a deacon for his blessing or to kiss his hand. Blessings are given by bishops and priests, so these expressions of honor are reserved for them alone.
All three degrees of major clergy wear the sticharion. The sticharion is a long-sleeved tunic that reaches all the way to the ground. It reminds the wearer that the grace of the Holy Spirit covers him as with a garment of salvation and joy. For deacons, the sticharion has wide sleeves and is made of a heavier fabric than that of the priest and bishop, who wear their sticharia under other vestments.
The second part of a deacon's vestments is the orarion. The orarion is a narrow band of material that the deacon wears wrapped around his body and draped over his left shoulder. It represents the grace of the Holy Spirit that in ordination anoints the deacon like oil. It is the principal vestment of the deacon and without it he cannot serve. When the deacon leads the people in prayers or invites them to attention he holds one end of his orarion in his right hand and raises it. The priest's epitrachelion and the bishop's omophorion are specialized types of the orarion.
The final parts of a deacon's vestments are the epimanikia. The epimanikia are cuffs that are worn around the wrists, tied by a long cord. These are also worn by the bishop and priest. They serve the practical purpose of keeping the inner garments out of the way during the services. They also remind the wearer that he serves not by his own strength but with the help of God.
Before the deacon can don any of his vestments, he must first receive the blessing of the bishop or priest with whom he is serving.