# entropy

[ en-truh-pee ]

/ ˈɛn trə pi /

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### noun

Thermodynamics.

- (on a macroscopic scale) a function of thermodynamic variables, as temperature, pressure, or composition, that is a measure of the energy that is not available for work during a thermodynamic process. A closed system evolves toward a state of maximum entropy.
- (in statistical mechanics) a measure of the randomness of the microscopic constituents of a thermodynamic system. Symbol: S

(in data transmission and information theory) a measure of the loss of information in a transmitted signal or message.

(in cosmology) a hypothetical tendency for the universe to attain a state of maximum homogeneity in which all matter is at a uniform temperature (heat death ).

a doctrine of inevitable social decline and degeneration.

## QUIZZES

#### QUIZ YOURSELF ON PARENTHESES AND BRACKETS APLENTY!

Set some time apart to test your bracket symbol knowledge, and see if you can keep your parentheses, squares, curlies, and angles all straight!

Question 1 of 7

Let’s start with some etymology: What are the origins of the typographical word “bracket”?

First appeared around 1750, and is related to the French word “braguette” for the name of codpiece armor.

First appeared in 1610, based on the French word “baguette” for the long loaf of bread.

First appeared in 1555, and is related to the French word “raquette” for a netted bat.

TAKE THE QUIZ TO FIND OUT ## OTHER WORDS FROM entropy

en·tro·pic [en-troh-pik, -trop-ik], /ɛnˈtroʊ pɪk, -ˈtrɒp ɪk/, adjectiveen·tro·pi·cal·ly, adverbDictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

## Example sentences from the Web for entropy

## British Dictionary definitions for entropy

entropy

/ (ˈɛntrəpɪ) /

### noun plural -pies

a thermodynamic quantity that changes in a reversible process by an amount equal to the heat absorbed or emitted divided by the thermodynamic temperature. It is measured in joules per kelvinSymbol: S See also law of thermodynamics

a statistical measure of the disorder of a closed system expressed by S = k log P + c where P is the probability that a particular state of the system exists, k is the Boltzmann constant, and c is another constant

lack of pattern or organization; disorder

a measure of the efficiency of a system, such as a code or language, in transmitting information

## Word Origin for entropy

C19: from en- ² + -trope

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

## Medical definitions for entropy

entropy

[ ĕn′trə-pē ]

### n.

For a closed thermodynamic system, a quantitative measure of the amount of thermal energy not available to do work.

A measure of the disorder or randomness in a closed system.

## Other words from entropy

en•tro′pic (ĕn-trō′pĭk, -trŏp′ĭk) adj.The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

## Scientific definitions for entropy

entropy

[ ĕn′trə-pē ]

A measure of the amount of energy in a physical system not available to do work. As a physical system becomes more disordered, and its energy becomes more evenly distributed, that energy becomes less able to do work. For example, a car rolling along a road has kinetic energy that could do work (by carrying or colliding with something, for example); as friction slows it down and its energy is distributed to its surroundings as heat, it loses this ability. The amount of entropy is often thought of as the amount of disorder in a system. See also heat death.

The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

## Cultural definitions for entropy

entropy

[ (en-truh-pee) ]

A measure of the disorder of any system, or of the unavailability of its heat energy for work. One way of stating the second law of thermodynamics — the principle that heat will not flow from a cold to a hot object spontaneously — is to say that the entropy of an isolated system can, at best, remain the same and will increase for most systems. Thus, the overall disorder of an isolated system must increase.

## notes for entropy

Entropy is often used loosely to refer to the breakdown or disorganization of any system: “The committee meeting did nothing but increase the entropy.”

## notes for entropy

In the nineteenth century, a popular scientific notion suggested that entropy was gradually increasing, and therefore the universe was running down and eventually all motion would cease. When people realized that this would not happen for billions of years, if it happened at all, concern about this notion generally disappeared.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.