| 释义 |
WordReference Random House Learner's Dictionary of American English © 2024ra•di•us /ˈreɪdiəs/USA pronunciation n. [countable], pl. -di•i /-diˌaɪ/USA pronunciation -di•us•es. - Mathematicsa straight line from the center of a circle or sphere to the circumference or surface:The radius of a circle is half the diameter.
- Mathematicsa circular area whose size can be measured by the length of a given radius:They searched every house within a radius of 50 miles.
WordReference Random House Unabridged Dictionary of American English © 2024ra•di•us (rā′dē əs),USA pronunciation n., pl. -di•i (-dē ī′),USA pronunciation -di•us•es. - Mathematicsa 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.
- Mathematicsthe length of such a line.
- any radial or radiating part.
- Mathematicsa 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.
- Anatomythe bone of the forearm on the thumb side. Cf. ulna (def. 1). See diag. under skeleton.
- Zoologya corresponding bone in the forelimb of other vertebrates.
- Mechanical Engineering[Mach. Now Rare.]the throw of an eccentric wheel or cam.
- Mechanical Engineeringa rounded corner or edge on a machined or cast piece of metal.
- Insects[Entomol.]one of the principal longitudinal veins in the anterior portion of the wing of an insect.
- Latin: staff, rod, spoke, beam, origin, originally, ray1
- 1590–1600
Collins Concise English Dictionary © HarperCollins Publishers:: radius /ˈreɪdɪəs/ n ( pl -dii / -dɪˌaɪ/, -diuses)- 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 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
- any radial or radiating part, such as a spoke
- (as modifier): a radius arm
- 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
Etymology: 16th Century: from Latin: rod, ray, spoke |