What does "fish, wine, and oil allowed" mean on a fast day?
A festal relaxation within a fast. Fish is permitted, along with wine and oil, while meat, dairy, and eggs are still kept back. This is the pattern on certain feasts within the fasting seasons, including the Annunciation and Palm Sunday in Great Lent and the Transfiguration in the Dormition Fast. On those days, the joy of the feast lightens the fast without ending it.