jay29 I would probably find any definition from a reputable philosophical dictionary acceptable.

Comment 20 by Jos Gibbons - Then Google one and copy-paste it here (linking to the source) and show it can’t be used to reach the conclusions for which the present definition was used. DO you even know such a definition? If not, how do you know the one used here is “wrong”?

Come to think of it, what is a reputable philosophical dictionary? (There's little enough consensus on what is reputable philosophy.) Not that there seem many to choose from online, & the ones I just looked at don't even seem to have definitions of the supernatural you could use to "prove" your "point". But if you can track one down I'll be all eyes.

It is indeed jay29 who is "begging the question", by asserting the existence of an undefined "supernatural" and then asking others to disprove this undefined and unevidenced assertion.

Any philosopher's definition of the "supernatural" is likely to be based on" imaginary concepts" in magical stories from mythology. "Some author made up a story about imaginary events", is not evidence.
(Harry Potter books and films, are not evidence of supernatural "wizard magic".)

In order to have any connection to reality or existence, some definition of "beyond" the normal/natural/ or science etc, needs to be made.

This "beyond ..xxx..... definition" - can only be made AFTER defining the "normal/natural/or science". Defining the properties of nature, (that is what science is and where its "boundaries" [if any] are), must be established before any "beyond" can be defined.
These would have to be physical boundaries - not merely boundaries of personal knowledge or understanding (as with the example given by Slightly Permanent @18).

As has been pointed out:- trying to define "beyond a boundary", without first defining the boundary and establishing evidence of its existence, is illogical.

As Steve says @16:-

Supernaturalism is nonsense because science has no limits. In fact, the idea of separating reality into naturalism and supernaturalism is itself nonsensical. It's like a child's drawing where a gap is left between land and sky. There are things that are real, and that is all we need to say.