1. Roman law. An established holiday or festival in the ecclesiastical calendar, used as a date in a legal instrument.
2. Hist. One of four principal days (feasts) of the year: March 25, the annunciation of the Virgin Mary; June 24, the birth of John the Baptist; September 28, the feast of St. Michael the Archangel; and December 21, the feast of St. Thomas the Apostle. • The four feast days were used as fixed dates (called “quarter-days”) for paying rent; before 1875, they were used as a reference point to set terms of courts. — Also termed feast day; feast-day.
