Empiricism is an epistemology. It holds that there is no basis for belief but that of the senses. Materialism is the metaphysical analogue of empiricism. Since it is by no means clear how the evidence of the senses could lead to belief in anything that is not material, the obvious conclusion is that nothing exists that is not material. It is typically opposed to wild flights of fancy and idealism (which some strange people (e.g., empiricists) think are the same thing).