n. In anatomy, a portion of the cerebral cortex concealed in the Sylvian fissure, consisting of five or six radiating convolutions, the gyri operti.n. In a Roman city, especially Rome itself, a building composed of distinct apartments let to several families; an apartment-house or tenement-house, in distinction from domus, an independent residence.n. In a smaller Roman city, especially Pompeii, a block of houses entirely surrounded by streets.