It's what they categorise it as in CD shops, even, I believe, on Smithsonian Folkways. It's a catchall term, not a genre name. it's just a broad category for the uncategorisable genres that don't belong to the broader ones and for a kind of "exotic" category. I'm sorry if I sounded like I thought that it did mean something. Most shops which sell CDS slam anything that doesn't fit the broader genre categories into "world music" which means any music which originates in places whose music styles are obscure and not really "popular", such as traditional West African music, for example. I hope this doesn't come off as angry or rude.