D defs.my
Entry 1 sense Webster, 1913

Entropy

/ĕn'-trəp-ē/ · En·tro·py · IPA /ˈɛntɹəpi/
01 n. A certain property of a body, expressed as a measurable quantity, such that when there is no communication of heat the quantity remains con…
  1. 1.
    A certain property of a body, expressed as a measurable quantity, such that when there is no communication of heat the quantity remains constant, but when heat enters or leaves the body the quantity increases or diminishes. If a small amount, h, of heat enters the body when its temperature is t in the thermodynamic scale the entropy of the body is increased by h ÷ t. The entropy is regarded as measured from some standard temperature and pressure. Sometimes called the thermodynamic function.(Thermodynamics) Also: thermodynamic function
    “The entropy of the universe tends towards a maximum.” — Clausius.