Any of the grooves or furrows separating the convolutions on the surface of the brain; = sulcus, n. 2b. Obsolete.

Described by or named after the anatomist Sylvius: applied to certain structures in the brain. the fissure between the anterior and middle lobes…

spec. A fissure between two convolutions of the brain.

With of and in the genitive, esp. in fissure of Rolando. Designating the central sulcus, which separates the frontal and parietal lobes on the…

Anatomy. (See quots. and cf. vallecula, n. 1.)

Anatomy. Originally: a fissure (sulcus) of the cerebral cortex which is wholly or partly concealed by an overlying convolution of the cerebral…

Anatomy. A gyrus partially or totally concealed by an overlying gyrus. Cf. subfissure, n. 2. Now rare or disused.