Luna
A holder for the consecrated host in a monstrance, typically used for the service of Benediction. It is also known as a lunette. The luna fits into the back of the monstrance and holds the host in an upright and visible position. The host is seen through the transparent glass, but it does not touch the glass of the monstrance. See Benediction of the Blessed Sacrament; see Monstrance.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.