Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “radius”

See all translations

radius

noun [C] uk   /ˈreɪ.di.əs/ ( plural radii ) us  

radius noun [C] (DISTANCE)

(the length of) a straight line joining the centre of a circle to its edge or the centre of a sphere to its surface: The radius of this wheel is 30 cm. This wheel has a radius of 30 cm. a distance from a central point: The station, shopping centre and school lie within a one-mile radius of the house.

radius noun [C] (BONE)

specialized anatomy the thicker of the two bones in the lower arm
(Definition of radius from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of radius?
Add Cambridge dictionaries to your browser to your website

Definitions of “radius” in other dictionaries

Word of the Day

thug

a man who acts violently, especially to commit a crime

Word of the Day

The way we move (Verbs for walking and running)

by Kate Woodford,
March 25, 2015
​​​ This week we’re looking at interesting ways to describe the way that people move. Most of the verbs that we’ll be considering describe how fast or slow people move. Others describe the attitude or state of mind of the person walking or running. Some describe both. Starting with verbs for walking slowly,

Read More 

crossfit noun

March 23, 2015
high-intensity strength training Two women in strappy dresses discussed how much weight they could snatch

Read More