foramen o·val·e 
(ō-vălē, -vālē, -vä-)
(ō-vălē, -vālē, -vä-)n.
An opening in the septum between the right and left atria of the heart, present in the fetus but usually closed soon after birth.
[New Latin forāmen ōvāle : Latin forāmen, opening + Medieval Latin ōvāle, neuter of ōvālis, oval.]