radian
	英 ['reɪdɪən]
美['redɪən]
	    
	
    - n. [数] 弧度
- n. (Radian)人名;(罗)拉迪安
 
    英英释意
	
	- 1. 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)