entropy

noun
en·​tro·​py | \ ˈen-trə-pē How to pronounce entropy (audio) \
plural entropies

Definition of entropy

1 thermodynamics : a measure of the unavailable energy in a closed thermodynamic system that is also usually considered to be a measure of the system's disorder, that is a property of the system's state, and that varies directly with any reversible change in heat in the system and inversely with the temperature of the system broadly : the degree of disorder or uncertainty in a system
2a : the degradation of the matter and energy in the universe to an ultimate state of inert uniformity Entropy is the general trend of the universe toward death and disorder.— James R. Newman
b : a process of degradation or running down or a trend to disorder The deterioration of copy editing and proof-reading, incidentally, is a token of the cultural entropy that has overtaken us in the postwar years.— John Simon
4 statistical mechanics : a factor or quantity that is a function of the physical state of a mechanical system and is equal to the logarithm of the probability for the occurrence of the particular molecular arrangement in that state
5 communication theory : a measure of the efficiency of a system (such as a code or a language) in transmitting information, being equal to the logarithm of the number of different messages that can be sent by selection from the same set of symbols and thus indicating the degree of initial uncertainty that can be resolved by any one message

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Other Words from entropy

entropic \ en-​ˈtrō-​pik How to pronounce entropic (audio) , -​ˈträ-​pik \ adjective
entropically \ en-​ˈtrō-​pi-​k(ə-​)lē How to pronounce entropically (audio) , -​ˈträ-​ \ adverb

Did You Know?

With its Greek prefix en-, meaning "within", and the trop- root here meaning "change", entropy basically means "change within (a closed system)". The closed system we usually think of when speaking of entropy (especially if we're not physicists) is the entire universe. But entropy applies to closed systems of any size. Entropy is seen when the ice in a glass of water in a warm room melts—that is, as the temperature of everything in the room evens out. In a slightly different type of entropy, a drop of food coloring in that glass of water soon spreads out evenly. However, when a nonphysicist uses the word, he or she is usually trying to describe a large-scale collapse.

Examples of entropy in a Sentence

Recent Examples on the Web At that temperature, the resulting glass would have an entropy as low as that of a crystal. Quanta Magazine, "Ideal Glass Would Explain Why Glass Exists at All," 11 Mar. 2020 This refers to the physical property known as entropy. Dennis Overbye, New York Times, "Just a Few Billion Years Left to Go," 4 Mar. 2020 Twistocaloric cooling relies on the relationship between heat energy and entropy. Sophie Bushwick, Scientific American, "A Simple Twist of Thermodynamics Could Lead to Greener Refrigeration," 21 Jan. 2020 That analysis, borrowed from medical science, measures the degree of order or disorder (that is, entropy) in the data. Scott K. Johnson, Ars Technica, "Forecasting El Niño with entropy—a year in advance," 28 Dec. 2019 The ultimately law of geopolitics is not the succession of hegemony from one superpower to another, but entropy: the diffusion of power among an ever-growing number of confident power centers. Parag Khanna, Quartz, "Everyone has moved past the US-China trade war—except the US and China," 16 Dec. 2019 The events of 1989 marked the beginning of the end of the first kind of era and the onset of a new age of entropy and chaos. David Kaiser, Time, "The Fall of the Berlin Wall Seemed Like a Victory for Democracy. 30 Years Later, Both Sides Are Losing," 7 Nov. 2019 And that’s the puzzle about thermodynamics and entropy and so on. Quanta Magazine, "A Defense of the Reality of Time," 16 May 2017 Su Lan is obsessed with a theory about how to create a world free of entropy, where things don’t fall apart – a poignant (if at times convoluted) metaphor for a parent’s responsibility in troubled times. Mark Athitakis, USA TODAY, "Love and physics collide in Meng Jin's wrenching Chinese-American tale 'Little Gods'," 12 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'entropy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of entropy

1867, in the meaning defined at sense 1

History and Etymology for entropy

International Scientific Vocabulary en- entry 2 + Greek tropē change, literally, turn, from trepein to turn

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Time Traveler for entropy

Time Traveler

The first known use of entropy was in 1867

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Statistics for entropy

Last Updated

26 Mar 2020

Cite this Entry

“Entropy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/entropy. Accessed 29 Mar. 2020.

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More Definitions for entropy

entropy

noun
en·​tro·​py | \ ˈen-trə-pē How to pronounce entropy (audio) \
plural entropies

Medical Definition of entropy

: a measure of the unavailable energy in a closed thermodynamic system that is also usually considered to be a measure of the system's disorder and that is a property of the system's state and is related to it in such a manner that a reversible change in heat in the system produces a change in the measure which varies directly with the heat change and inversely with the absolute temperature at which the change takes place broadly : the degree of disorder or uncertainty in a system

Other Words from entropy

entropic \ en-​ˈtrōp-​ik How to pronounce entropic (audio) , -​ˈträp-​ How to pronounce entropic (audio) \ adjective
entropically \ -​i-​k(ə-​)lē How to pronounce entropically (audio) \ adverb

More from Merriam-Webster on entropy

Britannica English: Translation of entropy for Arabic Speakers

Britannica.com: Encyclopedia article about entropy

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