1. Formal lack of pattern or organization
“entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity”
2. A measure of the disorder or randomness in a closed system.
3. A measure of the loss of information in a transmitted message.
4. The tendency for all matter and energy in the universe to evolve toward a state of inert uniformity.
5. Inevitable and steady deterioration of a system or society.
(Taken From [nullpointer.co.uk]'s article " Entropy, performance and gameplay" without permission.)
For the sake of this post, I'll be using the 2nd, 3rd and 5th definitions. The system will be any and all types of communication.
It is impossible to communicate at 100% efficiency, to convey the exact thought in which you are thinking. An individual's mind is too complex to generate the exact same complex thought in another individual without some variance occurring. It could be said then that this variance is something I'm calling "thought rot". The severity of rot is determined by the amount of entropy of any given communication system.
There is a variant level of entropy depending on whether the idea being conveyed is a logical or creative. In creative thought, the idea is abstract. In the verbal communication of any creation, there occurs a form of thought rot that deteriorates the idea, and it deteriorates based on each persons level of communication skills, as well as the number of times the idea is communicated.
This is why I think mods and projects that are created using more than 2 or 3 core people tend to not be able to progress to a finish, or finish with a more convoluted idea than the original iteration. When you keep a close, tight team (from my observations, and I could be wrong) the mod tends to actually come out, and come out closer to it's original idea (Minerva is one excellent example done by a lone mapper) than if it was released using a larger team.