radial

What it means

1. Arranged like rays that radiate from, or converge to, a common centre.

   The spokes on most modern bicycle wheels are tangential to the hub rather than radial.

   1 more example

   A doorknob of whatever roundish shape is effectively a continuum of levers, with the axis of the latching mechanism—known as the spindle—being the fulcrum about which the turning takes place. Applying a force tangential to the knob is essentially equivalent to applying one perpendicular to a radial line defining the lever.

   2012 March 28, Henry Petroski, “Opening Doors”, in American Scientist, volume 100, number 2, pages 112–3

2. geometryOf, or relating to a radius (line joining to a geometric centre).

   What is the relationship between arc length and radial length?

   1. geometryMoving or acting along a radius.

      radial velocity

In a sentence

The spokes on most modern bicycle wheels are tangential to the hub rather than radial.

Where it comes from

1. Latinradius
2. Medieval Latinradiālis“radial”
3. Englishradial

From Medieval Latin radiālis (“radial”), from Latin radius. By surface analysis, radius + -al.