An empiricist is a person who holds empiricism: they want ideas to rest on experience and tests, not on pure thought. The word can also describe a style of work — empiricist science, an empiricist teacher — meaning that person or field keeps coming back to what was actually tried. Famous names in the philosophy story include Locke and Hume, but you can be a small-e empiricist in daily life: you change the recipe only after you have tasted the result. Though actually, the belief itself is empiricism; empiricist names the person (or their way), not the -ism. People sometimes blur the two, as if empiricist already meant “the belief.”