coven
n.
"a gathering of witches," 1660s, earlier (c.1500) a variant of covent, cuvent early forms of convent. Association with witches arose in Scotland, but not popularized until Sir Walter Scott used it in this sense in "Letters on Demonology and Witchcraft" (1830).
Efter that tym ther vold meit bot somtymes a Coven, somtymes mor, somtymes les; bot a Grand Meitting vold be about the end of ilk Quarter. Ther is threttein persones in ilk Coeven; and ilk on of vs has an Sprit to wait wpon ws, quhan ve pleas to call wpon him. I remember not all the Spritis names; bot thair is on called "Swein," quhilk waitis wpon the said Margret Wilson in Aulderne; he is still clothed in grass-grein .... ["Criminal Trials in Scotland," III, appendix, p.606, confession of Issobell Gowdie in Lochloy in 1662]