mid-15c., "flywheel or pulley on a spindle," perhaps an alteration of whirl. Meaning "circle of leaves or flowers round a stem of a plant" is first recorded 1550s. Of seashells or other spiral structures, from 1828.
whorl (wôrl, wûrl)
A form that coils or spirals; a curl or swirl.
A turn of the cochlea or of the ethmoidal crest.
An area of hair growing in a radial manner.
One of the circular ridges or convolutions of a fingerprint.