crust

A more solid, dense or hard layer on a surface or boundary.

The external, hardened layer of certain foodstuffs, including most types of bread, fried meat, etc.

An outer layer composed of pastry

Th' impenetrable crust thy teeth defies.

They […] made the crust for the venison pasty.

The bread-like base of a pizza.

A slice of bread cut from the end of a loaf; the heel.

To cover with a crust.

The whole body is crusted over with ice.

Their minds are crusted over, like diamonds in the rock.

To form a crust.

, The Goblin Reign Boxed Set Thistle held her hand over the wound and pressed a wad of tree moss against it. "Don't move," she said. "Let it crust."