agiasma
The holy water (as well as the sacred place from where the water spurts), which the faithful drink, sprinkle or wash themselves in order to be healed.

arcosolium
(lat.) A tomb carved out of a wall (solium) with an arched niche (arcus) above it.

baptistery
The building or room used for Baptism. It had a font usually in the form of a cross. After the 6th c. the baptisteries constitute distinct constructions- octagonal, circular, cruciform- detached to the church or its courtyard.

cross- (groin-) vault
A vault formed over square or rectangular spaces by the interpenetration of two barrel-vaults of equal hight and diameter. The lines of the intersection form a diagonal cross.

Deesis
Iconographic theme, an image of intercession for the salvation of the human race, which represents Jesus as the central figure, between the Virgin and St. John the Baptist

diakonikon
An auxiliary chamber of the church, also known in early years as skeuophylakion, which could be a separate building attached to the church. There were kept the sacred vessels but sometimes also the offerings of the faithful, the archive or library. In Byzantine churches the diakonikon becomes the sacristy to the south of the Bema, corresponding to the prothesis to the north, and forming along with them the triple sanctuary. It usually has an apse projecting to the east.

dome
A characteristic element of Byzantine architecture. The dome is a hemispherical vault on a circular wall (drum) usually pierced by windows. The domed church emerges in the Early Byzantine years and its various types gradually prevail, while they are expanded in the Balkans and in Russia.

drum of dome
Part of the church, semicircular or polygonal, on which rises an hemispheric dome

katholikon
The main church in a monastic complex, heart of the monastic activity.

prothesis
Ιn ecclesiastical architecture, the sacristy to the north of the sanctuary. Usually it has an apse projecting to the east. It is the chamber where the eucharistic elements were prepared (Proskomide) before the Communion.

strategos ("general")
During the Roman period his duties were mainly political. Οffice of the Byzantine state´s provincial administration. At first the title was given to the military and political administrator of the themes, namely of the big geographic and administrative unities of the Byzantine empire. Gradually the title lost its power and, already in the 11th century, strategoi were turned to simple commanders of military units, responsible for the defence of a region.