Wheel spokes, e.g.

• Lines on a pie chart, e.g
• Two may make a diameter
• Halves of diameters
• Arm reinforcements organising raid to capture island
• Person who paints diameter and two lines in circle
• Hub projections
• Minute hands, say
• Geometry calculations
• Parts of some area calculations

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Radii \Ra"di*i\ (r[=a]"d[i^]*[imac]), n., pl. of Radius .