The answer to this question is rather nebulous. The dictionary definition is "A lacy shawl or head covering" but, today's definition is quite different and there are several opinions as to just what a fascinator is. To me, a fascinator can be anything from a fancy hair decoration to a cute hat with attitude. A hat is a serious fashion statement while a fascinator is a cuter more frivolous version. A fascinator can be worn on most occasions where you would wear a hat but I would not wear a fascinator to a very serious function such as a funeral.