Pronunciation: (ul'nu), [key]
—pl. -naePronunciation: (-nē), [key] -nas.
1. Anat.the bone of the forearm on the side opposite to the thumb. Cf. radius (def. 7). See diag. under skeleton.
2. a corresponding bone in the forelimb of other vertebrates.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.