On Mudcat, years ago, I found ceilidh to mean a kitchen party, usually of Irish music, but could just be trad/folk. This year, I read a great book which Micca sent me, about the Green Man Jack in the Green Festival in Hastings in which they call an English barn dance a ceilidh. So, I after talking with Micca, I've concluded it means either/or depending on where you are at!:-)