foramen of Monro n 1: the small opening (on both the right and left sides) that connects the third ventricle in the diencephalon with the lateral ventricle in the cerebral hemisphere [syn: {interventricular foramen}, {foramen of Monro}, {Monro's foramen}]
Foramen \Fo*ra"men\, n.; pl. L. {Foramina}, E. {Foramines}. [L., fr. forare to bore, pierce.] A small opening, perforation, or orifice; a fenestra. [1913 Webster] {Foramen of Monro} (Anat.), the opening from each lateral into the third ventricle of the brain. {Foramen of Winslow} (Anat.), the opening connecting the sac of the omentum with the general cavity of the peritoneum. [1913 Webster]