the brown, hard outer portion or surface of a loaf or slice of bread (distinguished from crumb).
2.
a slice of bread from the end of a loaf, consisting chiefly of this.
3.
the pastry covering the outside of a pie or other dish.
4.
a piece of stale bread.
5.
any more or less hard external covering or coating: a crust of snow.
6.
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), core1(def. 10).
7.
a scab or eschar.
8.
Slang. unabashed self-assertiveness; nerve; gall: He had a lot of crust going to the party without an invitation.
9.
deposit from wine, as it ripens during aging, on the interior of bottles, consisting of tartar and coloring matter.
10.
the hard outer shell or covering of an animal.
11.
AustralianSlang. a living or livelihood: What do you do for a crust?
–verb (used with object)
12.
to cover with or as with a crust; encrust.
13.
to form (something) into a crust.
–verb (used without object)
14.
to form or contract a crust.
15.
to form into a crust.
[Origin: 1275–1325; ME < AF, OF cruste, croste < L crusta hard coating, crust]
c.1325, from L. crusta "rind, crust, shell, bark," from PIE *krus-to-, from base *kreus- "to begin to freeze, form a crust" (cf. Skt. krud- "make hard, thicken;" Avestan xruzdra- "hard;" Gk. krystallos "ice, crystal," kryos "icy cold, frost;" Lett. kruwesis "frozen mud;" O.H.G. hrosa "ice, crust;" O.E. hruse "earth;" O.N. hroðr "scurf"). Meaning "outer shell of the earth" is from 1555. Crusty in the figurative sense of "short-tempered" is from 1570.
crustAudio Help (krŭst) Pronunciation Key
The solid, outermost layer of the Earth, lying above the mantle. ◇ The crust that includes continents is called continental crust and is about 35.4 to 70 km (22 to 43.4 mi) thick. It consists mostly of rocks, such as granites and granodiorites, that are rich in silica and aluminum, with minor amounts of iron, magnesium, calcium, sodium, and potassium. ◇ The crust that includes ocean floors is called oceanic crust and is about 4.8 to 9.7 km (3 to 6 mi) thick. It has a similar composition to that of continental crust, but has higher concentrations of iron, magnesium, and calcium and is denser than continental crust. The predominant type of rock in oceanic crust is basalt.
Main Entry: crust Pronunciation: 'kr&st Function: noun 1:SCAB 2 2: an encrusting deposit of serum, cellular debris, and bacteria present over or about lesions in some skin diseases (as impetigo or eczema) —crustverb
Crust\ (kr?st), n. [L. crusta: cf. OF. crouste, F. cro[^u]te; prob. akin to Gr. ????? ice, E. crystal, from the same root as E. crude, raw. See Raw, and cf. Custard.]1. The hard external coat or covering of anything; the hard exterior surface or outer shell; an incrustation; as, a crust of snow. I have known the statute of an emperor quite hid under a crust of dross. --Addison. Below this icy crust of conformity, the waters of infidelity lay dark and deep as ever. --Prescott. 2. (Cookery) (a) The hard exterior or surface of bread, in distinction from the soft part or crumb; or a piece of bread grown dry or hard. (b) The cover or case of a pie, in distinction from the soft contents. (c) The dough, or mass of doughy paste, cooked with a potpie; -- also called dumpling. Th' impenetrable crust thy teeth defies. --Dryden. He that keeps nor crust nor crumb. --Shak. They . . . made the crust for the venison pasty. --Macaulay. 3. (Geol.) The exterior portion of the earth, formerly universally supposed to inclose a molten interior. 4. (Zo["o]l.) The shell of crabs, lobsters, etc. 5. (Med.) A hard mass, made up of dried secretions blood, or pus, occurring upon the surface of the body. 6. An incrustation on the interior of wine bottles, the result of the ripening of the wine; a deposit of tartar, etc. See Beeswing.
Crust\, v. t. [imp. & p. p. Crusted; p. pr. & vb. n. Crusting.] [Cf. OF. crouster, L. crustare. See Crust, n. ] To cover with a crust; to cover or line with an incrustation; to incrust. The whole body is crusted over with ice. --Boyle. And now their legs, and breast, and bodies stood Crusted with bark. --Addison. Very foul and crusted bottles. --Swift. Their minds are crusted over, like diamonds in the rock. --Felton.
Crust\, v. t. [imp. & p. p. Crusted; p. pr. & vb. n. Crusting.] [Cf. OF. crouster, L. crustare. See Crust, n. ] To cover with a crust; to cover or line with an incrustation; to incrust. The whole body is crusted over with ice. --Boyle. And now their legs, and breast, and bodies stood Crusted with bark. --Addison. Very foul and crusted bottles. --Swift. Their minds are crusted over, like diamonds in the rock. --Felton.
Crys"tal\ (kr?s"tal), n. [OE. cristal, F. cristal, L. crystallum crystal, ice, fr. Gr. ????, fr. ???? icy cold, frost; cf. AS. crystalla, fr. L. crystallum; prob. akin to E. crust. See Crust, Raw.]1. (Chem. & Min.) The regular form which a substance tends to assume in solidifying, through the inherent power of cohesive attraction. It is bounded by plane surfaces, symmetrically arranged, and each species of crystal has fixed axial ratios. See Crystallization. 2. The material of quartz, in crystallization transparent or nearly so, and either colorless or slightly tinged with gray, or the like; -- called also rock crystal. Ornamental vessels are made of it. Cf. Smoky quartz, Pebble; also Brazilian pebble, under Brazilian. 3. A species of glass, more perfect in its composition and manufacture than common glass, and often cut into ornamental forms. See Flint glass. 4. The glass over the dial of a watch case. 5. Anything resembling crystal, as clear water, etc. The blue crystal of the seas. --Byron. Blood crystal. See under Blood. Compound crystal. See under Compound. Iceland crystal, a transparent variety of calcite, or crystallized calcium carbonate, brought from Iceland, and used in certain optical instruments, as the polariscope. Rock crystal, or Mountain crystal, any transparent crystal of quartz, particularly of limpid or colorless quartz.
Cus"tard\ (k?s"t?rd), n. [Prob. the same word as OE. crustade, crustate, a pie made with a crust, fr. L. crustatus covered with a crust, p. p. of crustare, fr. crusta crust; cf. OF. croustade pasty, It. crostata, or F. coutarde. See Crust, and cf. Crustated.] A mixture of milk and eggs, sweetened, and baked or boiled. Custard apple (Bot.), a low tree or shrub of tropical America, including several species of Anona (A. squamosa, reticulata, etc.), having a roundish or ovate fruit the size of a small orange, containing a soft, yellowish, edible pulp. Custard coffin, pastry, or crust, which covers or coffins a custard [Obs.] --Shak.
In*crust"\, v. t. [imp. & p. p. Incrusted; p. pr. & vb. n. Incrusting.] [L. incrustare; pref. in- in + crustare to cover with a crust: cf. F. incruster. See Crust.] [Written also encrust.]1. To cover or line with a crust, or hard coat; to form a crust on the surface of; as, iron incrusted with rust; a vessel incrusted with salt; a sweetmeat incrusted with sugar. And by the frost refin'd the whiter snow, Incrusted hard. --Thomson. 2. (Fine Arts) To inlay into, as a piece of carving or other ornamental object.
![[P]](http://cache.lexico.com/g/d/premium_mh.gif){kind=small}
Audio Help [kruhst] Pronunciation Key 
st)
