Personally, I don't like the description of entropy as disorder. Mathematically, it's a measure of spread of a probability distribution (the more spiked a dist

Personally, I don't like the description of entropy as disorder. Mathematically, it's a measure of spread of a probability distribution (the more spiked a distribution, the lower the entropy, which is an 'ordered' state insofar that things are arranged in specific places instead of randomly thrown all over the place). Depending on your point of view, I would describe entropy in physics as microscopic indeterminacy (essentially the number of microscopic states that are part of your statistical ensemble defined in terms of macroscopic constraints), or as microscopic freedom (essentially the volume of microscopic phase space accessible to time evolution of a system in thermodynamic equilibrium).