# symmetric

Definition from Wiktionary, the free dictionary

## Contents

## English[edit]

### Etymology[edit]

From Latin *symmetria* from Ancient Greek *συμμετρία* (summetría).

### Adjective[edit]

**symmetric** (*comparative* **more symmetric**, *superlative* **most symmetric**)

- Symmetrical.
- (set theory) Of a relation
*R*on a set*S*, such that*xRy*if and only if*yRx*for all members*x*and*y*of*S*(that is, if the relation holds between any element and a second, it also holds between the second and the first).*"Is a sibling of" is a***symmetric**relation.

- (cryptography) Using the same key (or keys that are trivially related) for both encryption and decryption.

#### Related terms[edit]

#### Translations[edit]

symmetrical —

*see*symmetricalof a relation R on a set S, such that xRy if and only if yRx for all members x and y of S