entropy in WordNet English dictionary

1. (thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
   "entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity"
   randomness  entropy  S 
   
2. (communication theory) a numerical measure of the uncertainty of an outcome
   "the signal contained thousands of bits of information"
   information  selective information  entropy