ˈəlnə noun
( plural ul·nae -ˌnē, -ˌnī ; or ulnas )
Etymology: New Latin, from Latin, elbow, arm, ell — more at ell
1. : the postaxial or inner one of the two bones of the forearm or corresponding part of the forelimb of vertebrates above fishes that in man forms with the humerus the elbow joint and serves as a pivot in rotation of the hand and that in many animals is fused with the radius and then often much reduced in size — see coronoid process , olecranon , semilunar , notch , sigmoid cavity
2. : the hypercoracoid bone of a fish