> Philosophy seems a term generally reserved for the stuff we don't understand yet and so is inherently kind of speculative. Once you have a definite answer it gets called science instead.

As someone has commented earlier, Philosophy applied is given a name but it's a sub-discipline of Philosophy.

> Understanding the world through experiment?

That's a decent enough definition. Science precludes so much of the world we know which I think people really fail to realise. It's why I think it's important for people to understand what Philosophy is and what Science isn't.

For example logic isn't science. Science presupposes it but it is NOT science. There are many such examples.

How do you know that understanding the world through experiment works? How do you know what it even means? What is understanding, concretely? How did we come to appreciate the utility or whatever of understanding the world through experiment.

Empiricism is a sub-strategy under the general banner of philosophy. It neither supercedes nor stands without philosophy.