radian
noun/ˈɹeɪdiən/
Etymology From radius + -an.
1
Geometry, Mathematics, Sciences In the International System of Units, the derived unit of plane angle: the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle.
- Derived terms
- microradian, milliradian, picoradian, radiansphere, steradian