Relating to or arranged like rays extending from a central point; having a pattern that spreads outward from a center.
From Latin radius meaning 'ray, spoke of a wheel, staff'. The geometric sense developed from the image of spokes radiating from the center of a wheel. The term became important in anatomy, engineering, and mathematics.
Your radial artery (the one where you check your pulse at your wrist) gets its name because it runs along the radius bone, which itself is named for being like a spoke of a wheel. Radial tires are called 'radial' because their internal cords run radially from the center to the edges, just like spokes - it's the same geometric principle in completely different applications.
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