[Nevermark]

I agree but with a slightly different definition.

There are no numbers in the real world, that require and infinitely long definition.

1/3 has infinitely many digits in decimal, but has a finite definition. So its good.

I would write down the opposite, a definition of an uncomputable, unnameable real, but there are not enough atoms in the universe (multi-verse, ...) to being to do that.