RADIUS Definition & Meaning

View synonyms for

radius

[ rey-dee-uhs ]

Phonetic (Standard)IPA

plural radii radiuses.

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.
the length of such a line.
any radial or radiating part.
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.
a field or range of operation or influence.
extent of possible operation, travel, etc., as under a single supply of fuel:
the flying radius of an airplane.
Anatomy. the bone of the forearm on the thumb side. Compare ulna ( def 1 ).
Zoology. a corresponding bone in the forelimb of other vertebrates.
Machinery Now Rare. the throw of an eccentric wheel or cam.
a rounded corner or edge on a machined or cast piece of metal.
Entomology. one of the principal longitudinal veins in the anterior portion of the wing of an insect.

radius

/ ˈ��ɪ��ɪə�� /

a straight line joining the centre of a circle or sphere to any point on the circumference or surface
the length of this line, usually denoted by the symbol r
the distance from the centre of a regular polygon to a vertex ( long radius ) or the perpendicular distance to a side ( short radius )
anatomy the outer and slightly shorter of the two bones of the human forearm, extending from the elbow to the wrist
a corresponding bone in other vertebrates
any of the veins of an insect's wing
a group of ray florets, occurring in such plants as the daisy
1. any radial or radiating part, such as a spoke
2. ( as modifier )
  a radius arm
the lateral displacement of a cam or eccentric wheel
a circular area of a size indicated by the length of its radius
the police stopped every lorry within a radius of four miles
the operational limit of a ship, aircraft, etc

radius

A line segment that joins the center of a circle or sphere with any point on the circumference of the circle or the surface of the sphere. It is half the length of the diameter.
The shorter and thicker of the two bones of the forearm or the lower portion of the foreleg.
See more at skeleton

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Origin of radius¹

First recorded in 1590–1600; from Latin: “staff, rod, spoke, beam,” originally, “ray”; ray ¹

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Origin of radius¹

C16: from Latin: rod, ray, spoke

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Examples have not been reviewed.

Search beyond a 40-mile radius - Remote, hybrid and flexible working open up opportunities further away.

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Our collecting really didn't happen very much outside of about a 100 meter radius of our base camp.

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With no imminent danger within our radius, he returns to Joe’s final words.

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We mixed each property’s soil — collected from four inches deep in multiple spots within a five- to 10-foot radius — in a plastic bag.

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"The radius should be put on them. So we know where they are and we have the freedom of the UK."

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