n.

1. 半径；半径距离；半径范围[C][the S][（+of）]
   There are three lakes within a radius of five miles.

   周围五英里之内有三个湖泊。

2. 周围，范围[the S][（+of）]
   within the radius of one's experience

   在个人经验范围之内

3. 辐射状部分；（车轮的）辐条[C]
4. 【解】桡骨[C]
5. 【动】径骨[C]
6. 【昆】径脉[C]

n.

1. a straight line from the centre to the circumference of a circle or sphere.
   ▸a radial line from the focus to any point of a curve.
2. a specified distance from a centre in all directions:
   there are plenty of pubs within a two-mile radius.
3. Anatomy  & Zoology  a bone of the forearm or forelimb, in humans the thicker and shorter of two.
4. Zoology  a radially symmetric feature in an echinoderm or coelenterate, e.g. an arm of a starfish.
5. Entomology  a main vein in an insect's wing.

v.