English noun: radian | |||
| 1. | radian (quantity) the unit of plane angle adopted under the Systeme International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees) | ||
| Synonyms | rad | ||
| Broader (hypernym) | angular unit | ||
| Part holonym | milliradian | ||