crust

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The hard outer portion or surface area of bread.
• noun A piece of bread consisting mostly of the hard outer portion.
• noun A piece of bread that has become hard and dry.
• noun A pastry shell, as of a pie or tart.
• noun A hard crisp covering or surface.
• noun A hard deposit formed on the interior of a wine bottle as the wine matures.
• noun The solid, outermost layer of the earth, lying above the mantle.
• noun The outermost solid layer of a planet or moon.
• noun The hard outer covering or integument of certain plants and animals, such as lichens and crustaceans.
• noun An outer layer or coating formed by the drying of a bodily exudate such as pus or blood; a scab.
• noun Informal Insolence; audacity; gall.
• intransitive verb To cover with a crust.
• intransitive verb To form into a crust.
• intransitive verb To become covered with a crust.
• intransitive verb To harden into a crust.

from The Century Dictionary.

• To cover with a crust or hard exterior portion or coating; overspread with anything resembling a crust; incrust.
• To coat or line with concretions. See crust, n., 3.
• To thicken or contract into a hard covering; concrete or freeze, as superficial matter.
• To crust-hunt.
• noun A hard external portion, of comparative thinness, forming a sort of coating over the softer interior part; any hard outer coat or coating: as, the crust of frozen snow; the crust of a loaf of bread; a thin crust of politeness.
• noun Specifically In geology: The exterior portion of the earth; that part of the earth which is accessible to examination.
• noun The solid portion of the earth, as opposed to its fused interior, many geologists and physicists believing that the interior of the earth must be in a more or less fluid condition.
• noun Matter collected or concreted into a solid body; an incrustation; specifically, a deposit from wine, as it ripens, collected on the interior of bottles, etc., and consisting of tartar and coloring matter.
• noun A piece of an outer coating or incrustation; specifically, an external or a dried and hard piece of bread.
• noun In zoology, a shell; a test; the chitinous or other hard covering of various animals, as crustaceans and insects.
• noun In anatomy and physiology, a coat or covering harder or denser than that which is covered; a pellicle; a crusta: as, the buffy coat or crust of inflammatory blood; the crust of a tooth.
• noun The part of the hoof of a horse to which the shoe is fastened.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To cover with a crust; to cover or line with an incrustation; to incrust.
• intransitive verb To gather or contract into a hard crust; to become incrusted.
• noun The hard external coat or covering of anything; the hard exterior surface or outer shell; an incrustation.
• noun The hard exterior or surface of bread, in distinction from the soft part or crumb; or a piece of bread grown dry or hard.
• noun The cover or case of a pie, in distinction from the soft contents.
• noun The dough, or mass of doughy paste, cooked with a potpie; -- also called dumpling.
• noun (Geol.) The exterior portion of the earth, formerly universally supposed to inclose a molten interior.
• noun (Zoöl.) The shell of crabs, lobsters, etc.
• noun (Med.) A hard mass, made up of dried secretions blood, or pus, occurring upon the surface of the body.
• noun An incrustation on the interior of wine bottles, the result of the ripening of the wine; a deposit of tartar, etc. See Beeswing.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A more solid, dense or hard layer on a surface or boundary.
• noun The external layer of most types of bread.
• noun Outer layer composed of pastry
• noun Bread foundation of pizza
• noun geology The outermost layer of the lithosphere of the Earth.
• noun uncountable Nerve, gall.
• noun crust punk (a subgenre of punk music)
• verb transitive To cover with a crust.
• verb intransitive To form a crust.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the trait of being rude and impertinent; inclined to take liberties