What is a Theory?

Well, most of us understand what is meant by the "Theory of Evolution" and have some common ground for discussion. Having said that, I know there are some YECs who demand precise definitions, as though we might confuse the evolution of waterproof fabrics with biological evolution. Personally, I think this is just a silly and superfluous argument and I'm not sure what the objective is.And I have to take issue with your statement that plate tectonic theory is just a description of geological facts. To the contrary, PT explains a huge amount of data from solid earth seismology to climate change.Also, I don't see how your two descriptons of 'theory' are are exclusive of each other. Please explain.