From Old French empirique, from Latin empiricus, from Ancient Greek ἐμπειρικός (empeirikós, “experienced”), from ἐμπειρία (empeiría, “experience, mere experience or practice without knowledge, especially in medicine, empiricism”), from ἔμπειρος (émpeiros, “experienced or practised in”), from ἐν (en, “in”) + πεῖρα (peîra, “a trial, experiment, attempt”). Not related to empire.