# permutation

/ˌpɝmjuˈteɪʃən/ (US) · /pˌɜːmjuːtˈeɪʃən/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/permutation
Updated: 2026-10-16

## Definition

one different way to order or arrange a set of things. If you change the order of three books, you make a new permutation.

For teachers: one of the possible orderings of a finite set of distinct elements, where changing the sequence creates a different case. Contrasted with combination, where order does not matter.

## Examples

- The lock has six possible permutations of numbers.
- The coach tries different permutations of players to find the strongest starting lineup.
- Mathematicians calculate the permutations of six books on a shelf to show how quickly possible orders grow even with small sets.

## Synonyms

arrangement

## Usage notes

- Often followed by 'of' to name the set being arranged.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.