ulna ul·na (ŭl'nə)
n. pl. ul·nas or ul·nae (-nē)
The larger bone of the two bones of the forearm, extending from elbow to wrist on the side opposite the thumb. Also called cubitus, elbow bone.
Plural ulnas or ulnae (ŭl'nē)
The longer of the two bones of the forearm or lower portion of the foreleg. See more at skeleton.