2. Something that covers, envelops, or conceals: Looking up into the sky was like looking at a dark blue mantle overspreading the earth.
A tragedy almost happened when the glamorous opera star, wearing an elegant mantle, leaned against the mantel of the fireplace and her mantle almost caught on fire.
2. A small circle of wire mesh in a gas or oil lamp that gives out incandescent light when heated by the flame it surrounds.
3. A role or position, especially one that can be passed from one person to another: "He assumed the mantle of the CEO of the company."
4. Something which envelops or covers something else: "The city was covered for over a week with a mantle of snow."
5. To unfold and to spread out the wings, like a mantle; for example, the way hawks do it.
6. The wings, shoulder feathers, and back feathers of a bird when colored differently from the rest of the body which enclose the body like a cloak.
7. The part of the brain that includes the convolutions (elevations on the surfaces of structures and the infolding of the tissues upon themselves), corpus callosum (arched bridge of nervous tissue that connects the two cerebral hemispheres, allowing communication between the right and left sides of the brain), and the fornix (fold in the shape of an arch of two bands of white fibers in the brain).
8. A tissue covering most of the body of mollusks which secretes the shell(s), and in shell-less mollusks , it is tough and protective.
The mantle is folded to enclose the mantle cavity, which contains the respiratory organs.
In squids, the mantle cavity has muscular walls which contract to force water out of the mantle cavity that propels the animal quickly through the water.
2. To become covered with a coating; such as, scum or froth on the surface of a liquid.
3. The spreading of their wings over food as is done by hawks.

Mantle convection has been compared to the motions which occur inside a pot of boiling tar.
Heat which is supplied from below lowers the viscosity of the tar and causes it to rise slowly to the surface, where it cools and sinks o the bottom to be reheated.
The "skin" which forms on the top is similar to the earth's lithosphere.
The hot plastic asthenosphere, part upper mantle and lower crust about 186 miles (300 kilometers) thick, separates the more brittle crust-mantle lithosphere above from the mesosphere below.
This is thought to be responsible for the movement of the lithospheric plates (crustal plates) which slowly "carry" the continents around the planet.
The more solid mesosphere, which is located below he asthenosphere, includes part of the upper and all of the lower mantle.
2. The nuclear zone of the developing neural tube between the marginal layer and the ependymal layer (covering of internal and external surfaces of the body, including the lining of vessels and other small cavities); which forms the gray matter of the central nervous system.
2. The layer of disintegrated and decomposed rock fragments; including soil, just above the solid rock of the earth's crust.