# entropy

/ˈɛntɹəpi/ (US) · /ˈɛntɹəpi/ (UK)

Source: https://englishreference.com/word/entropy
Updated: 2026-08-27

## Senses

### 1. scientific disorder

noun · CEFR C1 · Technical

a scientific measurement of how much energy is spread out or how messy a system is.

For teachers: A thermodynamic property representing the unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder.

- In physics, the law of entropy says that the universe is slowly becoming more disordered.
- The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time.

Usage: Uncountable in general scientific contexts; countable when referring to specific mathematical values.

### 2. general decline into chaos

noun · CEFR C2 · Academic · Literary

the natural way that things become disorganized or fall apart if you do not look after them.

For teachers: The inevitable and steady deterioration of a system or society; a metaphorical extension of the thermodynamic principle to social or organizational contexts.

- Without a manager to lead the team, the project quickly fell into entropy.
- The essay argues that the political entropy of the late empire was caused by a lack of central communication and crumbling infrastructure.

### 3. information theory

noun · CEFR C2 · Technical

a measure of how much information or 'noise' is in a signal or message.

For teachers: A mathematical measure of the uncertainty or information content associated with a random variable or data stream.

- The software uses entropy to create truly random passwords that are hard to guess.
- High entropy in a data set indicates a high degree of unpredictability, which is essential for robust cryptographic applications.

## Examples

- The messy room showed the power of entropy.
- In thermodynamics, the second law states that the total entropy of an isolated system can never decrease over time.
- While the architect intended for the building to stand as a monument to order, the creeping vines and crumbling masonry served as a stark reminder of inevitable entropy.

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