Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

  

English definition of “radius”

radius

noun [C]    /ˈreɪ·di·əs/ (plural radii  /ˈreɪ·diˌɑɪ/)
geometry (the length of) a straight line from the center of a circle to its edge: The supermarket, shopping mall, and school are all within a one-mile radius of the house (= are all less than a mile away from it).
(Definition of radius noun from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of radius

Definitions of “radius” in other dictionaries

Word of the Day

warm-up

something that you do to prepare yourself for an activity, especially gentle exercises before a physical activity

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More