Great Silence
In religious communities, the time between the last common prayer at night (compline or evensong) and the first common prayer in the morning (laud, prime, or morning prayer). Typically a period of solemn silence and quiet before and after sleep, it may be used for private reading and meditation. During this time one should avoid disturbing noises and speak only in emergencies.
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.