noun. 1. an anatomical empty space inside the body, like any of the heart's ventricles. 2. any of the four interlinked empty spaces in the brain, that act as reserves for cerebrospinal fluid. Both of the lateral ventricles communicates with the third by way of the interventricular foramen; the third and fourth ventricles communicate with one another, by way of the cerebral aqueduct, and with the spinal cord's central canas and the subarachnoid space.
VENTRICLE: "Ventricles are commonly referenced as cerebral ventricles, since the brain is the only place in the body where are housed."