<p><strong>Noun</strong></p><ul><li>the brown, hard outer portion or surface of a loaf or slice of bread (crumb)</li><li>a slice of bread from the end of a loaf, consisting chiefly of this</li><li>the pastry covering the outside of a pie or other dish</li><li>a piece of stale bread</li><li>any more or less hard external covering or coating: a crust of snow</li><li>Geology: the outer layer of the earth, about 22 miles (35 km) deep under the continents (continental crust) and 6 miles (10 km) deep under the oceans (oceanic crust)</li><li>a scab or eschar</li><li>Slang: unabashed self-assertiveness; nerve; gall: He had a lot of crust going to the party without an invitation</li><li>deposit from wine, as it ripens during aging, on the interior of bottles, consisting of tartar and coloring matter</li><li>the hard outer shell or covering of an animal</li><li>Australian Slang: a living or livelihood: What do you do for a crust?</li></ul><p><strong>Verb</strong></p><ul><li>(used with object) to cover with or as with a crust; encrust</li><li>to form (something) into a crust</li><li>(used without object) to form or contract a crust</li><li>to form into a crust</li></ul>