1. Structure, usually circular or polygonal, built over the tomb of a Christian martyr, so essentially a mausoleum. Hundreds of Christian churches owe their existence to martyria, which took their form from well-established Roman funerary types (exedrae, octagons, rotundas, etc.). The complex martyrium at Hierapolis in Phrygia, Turkey (early C5), had a plan derived from Nero's Golden House, Rome (C1).
2. Place in a church where Relics are deposited.
3. Structure created on a site where witness to the Christian faith was borne.
Cruickshank (ed.) (1996);
"martyrium." A Dictionary of Architecture and Landscape Architecture. . Encyclopedia.com. (July 17, 2018). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/martyrium
"martyrium." A Dictionary of Architecture and Landscape Architecture. . Retrieved July 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/martyrium