An ordinary weekday in the liturgical calendar, a day that is neither a feast nor a fast. A ferial day is understood as an extension of the preceding Sunday. The collect and proper readings for the Sunday eucharist are used in weekday celebrations of the eucharist unless otherwise provided. Ferial days became important in the western church in the early middle ages as daily Mass became customary. The term originally meant "holiday" or "day of rest" in Latin.
Feria, or Ferial Day
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.