Meaning of triradius

tri•ra•di•us

Pronunciation: (trī-rā'dē-us), [key]
— pl. -di•i -di•us•es.
  1. a-shaped group of ridges on the palm of the hand at the base of each finger.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.