I really don't know how to explain it, But anyway it's used in Khaliji dialect, and the origin of the word is ويل and it has a lot of meanings depends on the context it could mean Destruction, Torment or heartbreak. For Example: وَيْـل للمشركين But nowadays it's used in songs as expression of the feeling one experience because of lost of someone, or if someone mess up something he or she will say يا ويلي . And that's what I got I hope I explained it good enough.