1) Assembly 2) French day of worship 3) French word used in English 4) Halloween assemblage 5) Japanese musical trio 6) Midnight assembly 7) Midnight assembly of witches 8) Midnight meeting of witches 9) Midnight witch assembly 
• (n.) In mediaeval demonology, the nocturnal assembly in which demons and sorcerers were thought to celebrate their orgies.
(from the article `witchcraft`) ...accomplish magical deeds, and to desecrate the crucifix and the consecrated bread and wine of the Eucharist (Holy Communion). It was also believed ...
Any one of the eight Wiccan holidays. The solstices and equinoxes comprise the minor Sabbats. The cross-quarter days make up the major Sabbats. 
A Witch`s festival/holiday. The eight holy days sacred to Wiccans. Witches call Imbolc, Beltane, Lughnasadh, and Samhain the Greater Sabbats, and the Solstices and Equinoxes the Lesser Sabbats. 
Sab'bat noun [ See Sabbath .] In mediæval demonology, the nocturnal assembly in which demons and sorcerers were thought to celebrate their orgies. 
[n] - a midnight meeting of witches to practice witchcraft and sorcery
witches` Sabbath noun a midnight meeting of witches to practice witchcraft and sorcery; in the Middle Ages it was supposed to be a demonic orgy