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Meaning of radius

ra•di•us

Pronunciation: (rā'dē-us), [key]
— pl. -di•i -di•us•es.
  1. a straight line extending from the center of a circle or sphere to the circumference or surface: The radius of a circle is half the diameter.
  2. the length of such a line.
  3. any radial or radiating part.
  4. a circular area having an extent determined by the length of the radius from a given or specified central point: every house within a radius of 50 miles.
  5. a field or range of operation or influence.
  6. extent of possible operation, travel, etc., as under a single supply of fuel: the flying radius of an airplane.
  7. the bone of the forearm on the thumb side. Cf.(def. 1). See diag. under
  8. a corresponding bone in the forelimb of other vertebrates.
  9. the throw of an eccentric wheel or cam.
  10. a rounded corner or edge on a machined or cast piece of metal.
  11. one of the principal longitudinal veins in the anterior portion of the wing of an insect.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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