| 释义 |
radius /rāˈdi-əs/ noun (pl radii /rāˈdi-ī/ or raˈdiuses)- A straight line from the centre to the circumference of a circle or surface of a sphere (geometry)
- A radiating line
- Anything placed like a radius, such as the spoke of a wheel, the movable arm of a sextant, etc
- A radial plane of symmetry in a coelenterate
- A line from a fixed point (eg the focus of a conic) to a point on a curve
- The outer bone (in supine position) of the forearm in humans, or its equivalent in other animals
- A barbule of a feather
- The third vein of an insect's wing
- A ray-flower or the ray-flowers of a head collectively (rare)
- A distance from a centre, conceived as limiting an area or range
ORIGIN: L radius a rod, spoke, ray raˈdial adjective see separate entry radius of curvature noun (geometry) Of any curve, the radius of the circle which can be superimposed on it on the concave side radius vector noun (pl radii vectōˈres /-rēz/) A straight line joining a fixed point and a variable point |