lunate bone

n.
  1. The second of three bones forming the proximal row of bones in the wrist between the scaphoid and triquetrum bones and articulating with the radius, scaphoid, triquetrum, hamate, and capitate bones.semilunar bone
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.