n. In Roman antiquity, a voluminous rectangular mantle for men, corresponding to the Greek himation (see himation), and considered at Rome, because worn by Greek savants, as the particular dress of philosophers; also, a toga or other outer garment; a curtain, etc., of rectangular shape.n. Eccles.: In the early church, a large mantle worn by Christian philosophers, ascetics, and monks.n. A vestment worn by certain bishops, especially patriarchs and metropolitans.n. An alter-cloth; a frontal or pall.n. In conchology, the mantle, mantle-flap, or mantle-skirt of a mollusk, an outgrowth of the dorsal body-wall.n. In ornithology, the mantle; the stragulum; the back and folded wings together, in any way distinguished, as by color in a gull, etc.n. 5. A cirro-stratus cloud when it forms a uniform sheet over the whole sky.n. The cerebral cortex, or that portion of it which forms the roof and sides of the lateral ventricles: this is termed the pallium, or brain mantle, as distinguished from the stem of the brain on which it rests.