ra·di·us 
/ˈreɪdijəs/ noun
plural ra·dii /ˈreɪdijəs/ noun /ˈreɪdiˌaɪ/ [count] 1 technical : a straight line from the center of a circle or sphere to any point on the outer edge
▪ Measure the radius of the circle. ; also : the length of this line
▪ a radius of 10 inches — see picture at geometry; compare diameter 2 : an area that goes outward in all directions from a particular place
▪ The new museum is expected to draw people from a wide radius. ▪ More than 100,000 students live within a 10-mile radius of the university. [=within 10 miles of the university] ▪ There are three restaurants within a one-block radius of our apartment. 3 medical : the bone in the lower part of your arm on the same side as your thumb — see picture at human
▪ Measure the radius of the circle. ; also : the length of this line
▪ a radius of 10 inches — see picture at geometry; compare diameter
▪ The new museum is expected to draw people from a wide radius. ▪ More than 100,000 students live within a 10-mile radius of the university. [=within 10 miles of the university] ▪ There are three restaurants within a one-block radius of our apartment.
