• (n.) A transverse commisure in the posterior part of the roof of the third ventricle of the brain; the posterior cerebral commisure.
Post·com'mis·sure noun [ Prefix post- + commisure .] (Anat.) A transverse commisure in the posterior part of the roof of the third ventricle of the brain; the posterior cerebral commisure. B. G. Wilder.