rubral,a.Anat.|ˈruːbrəl| [f. L. ruber, rubr- red + -al1.] Of or pertaining to the red nucleus of the brain. 1954[see rubro-].1972M. L. Barr Human Nervous System vii. 110/2 A few rubral efferents enter the cerebellum through the superior peduncle to end in cerebellar nuclei.