Empirical
Etymology
From Greek "empeirikos," "experienced," from "empeiria" ("experience"), built from "en" ("in") and "peira" ("trial, attempt"). The Empirics were an ancient school of physicians who trusted observation over grand theory. That contrast — evidence gathered by trial versus reasoning from first principles — is exactly what the modern word carries.
adjective · /em-PEER-ih-kul/
Based on observation, measurement, or experiment rather than on theory alone.
What it names
Knowledge earned by looking at the world — reach for it to mark the difference between what the data actually show and what a model predicts they should.
Example
The claim sounded plausible, but there was no empirical evidence that the treatment actually worked.
Related idea
The natural foil is anecdotal: anecdotal support is a handful of personal stories, while empirical support comes from systematic observation you could repeat.