Vestibule

(zes'-tib-itl). A porch or threshold. V., Aortic, the space formed by the left ventricle adjoining the root of the aorta. V. of the Ear, the oval cavity of the internal ear, which forms the entrance to the cochlea. V. of the Mouth, that portion of the mouth outside of the teeth. V. of the Nose, the external nostrils. V. of the Ventricles, the entrance to the ventricles of the brain. V. of the Vulva. See Bulbi vestibuli. Viability (z'i-ab-il'-it-e). Ability to live; applied to the condition of a child at the time of birth.