1. Antique chapel, sacellum, or shrine.
2. Cella or adytum of a Roman temple.
3. That part of the chancel or choir in the vicinity of the high-altar, normally defined by the altar-rails, i.e. the sanctuary.
4. Piscina in a church.
"sacrarium." A Dictionary of Architecture and Landscape Architecture. . Encyclopedia.com. (August 19, 2018). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/sacrarium
"sacrarium." A Dictionary of Architecture and Landscape Architecture. . Retrieved August 19, 2018 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/sacrarium