entropy

EN-truh-pee /ˈɛntrəpi/
nounC1GREGMATCATUPSC
academictechnicalliterary

A thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work; often interpreted as a measure of disorder or randomness.

In strict physics, entropy is about energy dispersal and the number of ways a system can be arranged. In casual or literary use, it is a metaphor for inevitable decline, chaos, or decay.

The story behind the word. Coined in 1865 by German physicist Rudolf Clausius, 'entropy' was built from the Greek prefix 'en-' (in) and 'trope' (a turning, transformation). Clausius deliberately designed the word to sound like 'energy' to show how closely related the two concepts are.

Word relationships

  • disorder: Disorder is a general state of untidiness or lack of organization, while entropy is a precise, measurable physical state of energy distribution.
  • order: Order represents a structured, low-probability arrangement of a system, which corresponds to low entropy.

Commonly confused with

  • enthalpy: Entropy measures the disorder or energy dispersal of a system, whereas enthalpy measures the total heat content of that system.

Word family

  • entropic (adjective): Relating to or characterized by entropy.
  • entropically (adverb): In an entropic manner.

Collocations

  • increase entropy
  • maximum entropy
  • entropy of a system
  • law of entropy

Example sentences

  • "The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time." Explanation of the Second Law of Thermodynamics
  • "The law that entropy always increases holds, I think, the supreme position among the laws of Nature." Famous literary/scientific quote (The Nature of the Physical World by Arthur Eddington (1928))

Memory hook

Think of 'enter trophy'—if you enter a trophy room and throw a party, the structured order will quickly turn into complete chaos and disorder. Energy dispersing into disorder.

When not to use

Avoid using it in precise scientific contexts to mean simple 'messiness' (like a messy bedroom) without acknowledging its thermodynamic definition of energy states.

Fun facts

  • The concept of entropy led to the theory of the 'Heat Death of the Universe,' which suggests that the universe will eventually reach a state of maximum entropy where all energy is evenly distributed, and no useful work can ever be done again.
LangBlitz
Take your vocabulary further with LangBlitz

Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.