Dirt vs. soil, disease vs. disorder

OK, let's get some things clear, by definition if necessary. So a lot of plant experiments, especially those done in glass houses in pots require a growth medium for the plants. While mixing up a batch for some 240 pots, a security person on rounds came by and said, "So are you mixing up some dirt?"  Our stock answer followed, "No, dirt is something you find under your finger nails and in certain types of books and movies."  "We're mixing up some soil." This does mean that mixing soil can result in dirt under your finger nails. Similarly and widely misused are the terms disease and disorder. A disease is an illness that has a causative organism, a disease organism. A disorder is has a genetic or nutritional basis, but no causative organism is involved. Unfortunately the two terms are thrown around willy-nilly and used as basically interchangeable. So let's be a little more precise out there, people.