What are 'real' and 'synthetic' Method parameters in Java?

Looking into j.l.r.Executable class I've found a method called hasRealParameterData() and from its name and code context I assume that it tells whether a particular method has 'real' or 'synthetic' params.

If I take e.g. method Object.wait(long, int) and call hasRealParameterData() it turns out that it returns false which is confusing to me, as the method is declared in Object class along with its params.

From this I've got a couple of questions:

1. What are 'real' and 'synthetic' Method parameters and why Java believes that params of Object.wait(long, int) are not 'real'?
2. How can I define a method with 'real' params?