the brown, hard outer portion or surface of a loaf or slice of bread ( distinguished from crumb ).

a slice of bread from the end of a loaf, consisting chiefly of this.

the pastry covering the outside of a pie or other dish.

a piece of stale bread.

any more or less hard external covering or coating

a crust of snow.

Geology . the outer layer of the earth, about 22 mi. (35 km) deep under the continents and 6 mi. (10 km) deep under the oceans. Compare mantle ( def. 3 ) , core 1 ( def. 10 ) .

a scab or eschar.

Slang . unabashed self-assertiveness; nerve; gall

He had a lot of crust going to the party without an invitation.

deposit from wine, as it ripens during aging, on the interior of bottles, consisting of tartar and coloring matter.

the hard outer shell or covering of an animal.

Australian Slang . a living or livelihood

What do you do for a crust?

to cover with or as with a crust; encrust.

to form (something) into a crust.

to form or contract a crust.

to form into a crust.

noun

band , bloom , border , caking , coat , concretion , covering , edge , encrustation , film , hull , incrustation , integument , layer , outside , rind , scab , shell , skin , surface , verge , assumption , audaciousness , audacity , boldness , brashness , brazenness , cheek , cheekiness , chutzpah , discourtesy , disrespect , effrontery , face , familiarity , forwardness , gall , impertinence , impudency , incivility , insolence , nerve , nerviness , overconfidence , pertness , presumptuousness , pushiness , rudeness , sassiness , sauciness , coating , harden , incrustation.--v. incrust