“Validation is the process of determining the degree to which a model or simulation is an accurate representation of the real world from the perspective of the intended uses of the model or simulation. ”

Establishing fitness-for-use, same idea.

validate-to make valid; substantiate; confirm

Does that sound like a good way to start referring to tests of hypotheses?

Of course, I know many in this field think the duty of science is to vindicate the paradigm and thus the models, it is truly perverse that studies start out setting a goal of confirming models, rather than testing them. This is not merely un-Popperian but thoroughly opposite that-the normal procedure would be to try as hard as possible to test models until they break-if you can’t, that heightens confidence in them, if you can, something is wrong and so some revision is required-maybe something dramatic, maybe subtle. The resistance to falsification and the disturbing replacement with “verification” may mostly be a problem of semantics, but it doesn’t inspire confidence.

“… if someone demands that climate models be “validated” (or else the models aren’t credible) then they should have an idea of what that means.”

Do you really mean this??

I am not allowed to require validation of claims by EXPERTS simply because I am not versed in their area of practice??

No wonder snake oil salesmen are so successful!!!