uncinate process

Noun

 * 1)  A sickle-shaped extension of the ethmoid bone that projects posteroinferiorly from the ethmoidal labyrinth and articulates with the inferior nasal conchae.
 * 2)  A small portion of the head of the pancreas that extends to the back of the superior mesenteric vein  and ends at the superior mesenteric artery.
 * 3)  A hook-shaped upward projection arising from each lateral border of the upper surface of the vertebral bodies of several cervical vertebrae (C3–C7).
 * 4)  A bony extension that projects caudally from the vertical segment of each rib, found in most birds, reptiles, and the early amphibian Ichthyostega.