- Radius is a line from the center to the outside of a circle or sphere.
An example of radius is the spoke a bike wheel.
- The definition of a radius is a circular limit or a boundary of a specific distance which is drawn from a specific point.
An example of radius is a restaurant located within five miles of a house.
The radius of this wheel is indicated by the spokes.
nounpl. radii or radiuses
- a raylike or radial part, as a spoke of a wheel
- any straight line extending from the center to the periphery of a circle or sphere
- the length of such a line
- the circular area or distance limited by the sweep of such a line: no house within a radius of five miles
- the distance a ship or airplane can travel and still return to its point of origin without refueling
- an extent, scope, range, etc. of a limited or specified kind: within the radius of one's experience
- the shorter and thicker of the two bones of the forearm on the same side as the thumb
- a corresponding bone of the forelimb of a four-legged animal
- any of the planes of division of the body of a radially symmetrical animal
- any of various longitudinal veins in the wing of an insect
Origin of radiusClassical Latin rod, spoke (of a wheel), hence radius, ray (of light), uncertain or unknown; perhaps akin to radix, root
nounpl. ra·di·i or ra·di·us·es
- Abbr. r or rad. Mathematics a. A line segment that joins the center of a circle with any point on its circumference.b. A line segment that joins the center of a sphere with any point on its surface.c. A line segment that joins the center of a regular polygon with any of its vertices.d. The length of any such line segment.
- A circular area measured by a given radius: every family within a radius of 25 miles of the city center.
- A bounded range of effective activity or influence: the operating radius of a helicopter.
- A radial part or structure, such as a mechanically pivoted arm or the spoke of a wheel.
- Anatomy a. A long, prismatic, slightly curved bone in humans, the shorter and thicker of the two forearm bones, located on the lateral side of the ulna.b. A similar bone in many other vertebrates.
Origin of radiusLatin, ray, spoke of a wheel, radius.
(plural radii or radiuses)
From Latin radius (“ray”)
radius - Computer Definition
An Internet protocol used for authentication, authorization, and accounting of end users seeking to gain access to internal computer resources, generally through a network access server (NAS) or, for remote users, by dialing into a remote access server (RAS). Originally developed by Livingston Enterprises, RADIUS was later described by the IETF in RFCs 2058 and 2059 and is currently described in RFCs 2865 and 2866. See also authentication, authorization, IETF, NAS, RAS, and RFC.