Empirical means based on observation, experience, or experiment. When you know something empirically, you know it because you've actually seen it, tested it, or experienced it yourself.

A scientist conducts empirical research by running experiments and recording what actually happens. If you wonder whether plants grow faster with music, an empirical approach means setting up an experiment: growing identical plants, playing music for some but not others, and measuring the results. Your conclusion would be empirical because it comes from real observations.

Empirical evidence is particularly valuable because it's harder to dispute than opinions or guesses. When a doctor says a medicine works, she's relying on empirical studies where researchers tested it on real patients and recorded the outcomes. When you tell your friend that studying in short bursts works better than cramming, your claim becomes empirical if you've actually tried both methods and tracked your test scores.

Today, empirical knowledge forms the foundation of science, distinguishing it from pure mathematics or philosophy, where some truths can be discovered through reasoning alone.