radius meaning and definition

RADIUS noun

Definition of radius (noun)

1. the length of a line segment between the center and circumference of a circle or sphere
   • synonyms: r
2. a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)
3. a circular region whose area is indicated by the length of its radius
   • "they located it within a radius of 2 miles"
4. the outer and slightly shorter of the two bones of the human forearm
5. support consisting of a radial member of a wheel joining the hub to the rim
   • synonyms: spoke, wheel spoke