| Noun | 1. | radius - the length of a line segment between the center and circumference of a circle or spherediam, diameter - the length of a straight line passing through the center of a circle and connecting two points on the circumference semidiameter - the apparent radius of a celestial body when viewed as a disc from the earth radius of curvature - the radius of the circle of curvature; the absolute value of the reciprocal of the curvature of a curve at a given point length - the linear extent in space from one end to the other; the longest horizontal dimension of something that is fixed in place; "the length of the table was 5 feet" | |
| 2. | radius - a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)straight line - a line traced by a point traveling in a constant direction; a line of zero curvature; "the shortest distance between two points is a straight line" | |
| 3. | radius - a circular region whose area is indicated by the length of its radius; "they located it within a radius of 2 miles"region, part - the extended spatial location of something; "the farming regions of France"; "religions in all parts of the world"; "regions of outer space" | |
| 4. | radius - the outer and slightly shorter of the two bones of the human forearmforearm - the part of the superior limb between the elbow and the wrist | |
| 5. | radius - support consisting of a radial member of a wheel joining the hub to the rimcartwheel - a wheel that has wooden spokes and a metal rim support - any device that bears the weight of another thing; "there was no place to attach supports for a shelf" | |