noun (n)

• the length of a line segment between the center and circumference of a circle or sphere(noun.attribute)

  Synonym:
  r
  

  source: wordnet30
• a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)(noun.shape)

  source: wordnet30
• a circular region whose area is indicated by the length of its radius(noun.location)

  Example:
  They located it within a radius of 2 miles.
  

  source: wordnet30
• the outer and slightly shorter of the two bones of the human forearm(noun.body)

  source: wordnet30
• support consisting of a radial member of a wheel joining the hub to the rim(noun.artifact)

  Synonym:
  spoke, wheel spoke
  

  source: wordnet30
• A right line drawn or extending from the center of a circle to the periphery; the semidiameter of a circle or sphere.(noun)

  source: webster1913