**En"tro*py** (?), n. [Gr. a turning in; in + a turn, fr. to turn.] Thermodynamics

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*.

The **entropy** of the universe tends towards a maximum.
*Clausius.*

© Webster 1913.