entropy

IPA/ˈentrəpi/
KK[ˈɛntrəpi]IPA/ˈentrəpi/

entropy — noun

1. the level of disorder in a system, organization, or situation as it becomes less

1.nounC2
Definition

the level of disorder in a system, organization, or situation as it becomes less organized over time

Example

After the storm, fallen signs and broken wires added to the city's entropy.

physical disorder spreading through a system

Without clear rules, the volunteer group drifted toward entropy within a month.

move toward entropy in an organization

Common collocations
  • high entropy
  • low entropy
  • social entropy
  • drift toward entropy
Synonyms
  • disorder

    the broad everyday word; less technical than entropy

  • chaos

    stronger and more dramatic, often suggesting complete confusion

  • randomness

    focuses on lack of pattern rather than general mess

Antonyms
  • order

    a state where parts are arranged in a controlled way

  • stability

    emphasizes steadiness rather than disorder

Grammar Patterns

entropy in + system/organization

high/low entropy

move toward entropy

Usage Note

This broad sense is often used outside science for any setup that grows harder to control or keep tidy. Distinguish it from sense 2, which is a technical physics quantity, and sense 3, which measures unpredictability in information.

2. in physics, a quantity showing how much of a system's energy has spread out so f

2.nounC2
Definition

in physics, a quantity showing how much of a system's energy has spread out so far that it can no longer do useful work

Example

In class, Amani learned that hotter steam carries more entropy than ice.

compare entropy across physical states

The chart showed entropy rising as the sealed gas spread out.

entropy rises as particles spread out

Common collocations
  • measure entropy
  • calculate entropy
  • system entropy
  • entropy change

Grammar Patterns

entropy of + system

calculate/measure entropy

entropy rises/falls

Usage Note

This sense belongs to thermodynamics and usually appears with verbs such as calculate, measure, increase, and record. Unlike sense 1, it is not just about visible mess; it names a formal property of a physical system.

3. in information theory, a number showing how unpredictable a message or result is

3.nounC2
Definition

in information theory, a number showing how unpredictable a message or result is, and therefore how much information it contains

Example

Hugo said the scrambled code had high entropy because no pattern repeated.

high entropy means low predictability

Ishaan reduced the message's entropy by replacing random symbols with dates.

reduce entropy by making patterns clearer

Common collocations
  • high entropy
  • low entropy
  • message entropy
  • signal entropy
Synonyms
  • uncertainty

    the nearest plain-English idea, though less technical

  • randomness

    focuses on lack of pattern rather than the formal numerical measure

Antonyms

Grammar Patterns

entropy of + message/signal

high/low entropy

reduce/increase entropy

Usage Note

This sense is used for codes, signals, passwords, and messages, where the key idea is how hard the next part is to predict. Distinguish it from sense 2, which deals with energy in physical systems rather than information.

Synonym discussion

Sense: noun/1

Entropy overlaps with several words about lack of order, but each highlights a different idea. Disorder is the broad everyday word for things not being arranged properly. Chaos is stronger and suggests severe confusion or loss of control. Randomness focuses on the absence of pattern. Uncertainty is closer to the information-theory sense, where the question is how hard the next result or symbol is to predict. Entropy is the most technical term of the group: in science it is a measurable quantity, while in general writing it is often used more metaphorically for a system drifting toward disorder.

entropy ↗disorder ↗chaos ↗randomnessuncertainty ↗

Common collocations

Nouns

Verbs

Phrases

  • high entropy
  • low entropy
  • measure entropy
  • entropy of a system

Adjectives

Prepositions

Etymology

GreekEnglish

The scientific term was formed in the nineteenth century from Greek en- ('in') and trope ('turning' or 'change'). It first named the way energy in a physical system becomes more spread out, and later the word was extended to general disorder and to information theory.

First known use

1867

1867, in the meaning defined at sense 1