crust

[ kruhst ]

noun

1. the brown, hard outer portion or surface of a loaf or slice of bread ( 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 miles (35 km) deep under the continents continental crust and 6 miles (10 km) deep under the oceans oceanic crust. Compare mantle ( def 3 ), core ¹( 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. Australian Slang. a living or livelihood:

    What do you do for a crust?

verb (used with object)

1. to cover with or as with a crust; encrust.
2. to form (something) into a crust.

verb (used without object)

1. to form or contract a crust.
2. to form into a crust.

crust

/ krʌst /

noun

1. 1. the hard outer part of bread
   2. a piece of bread consisting mainly of this
2. the baked shell of a pie, tart, etc
3. any hard or stiff outer covering or surface

   a crust of ice

4. the solid outer shell of the earth, with an average thickness of 30–35 km in continental regions and 5 km beneath the oceans, forming the upper part of the lithosphere and lying immediately above the mantle, from which it is separated by the Mohorovičić discontinuity See also sial sima
5. the dry covering of a skin sore or lesion; scab
6. a layer of acid potassium tartrate deposited by some wine, esp port, on the inside of the bottle
7. the hard outer layer of such organisms as lichens and crustaceans
8. slang.
   impertinence
9. slang.
   a living (esp in the phrase earn a crust )

verb

1. to cover with or acquire a crust
2. to form or be formed into a crust

crust

/ krŭst /

1. The solid, outermost layer of the Earth, lying above the mantle.
2. ◆ 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.
3. ◆ 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.

crust

1. In geology , the outermost layer of the Earth . It overlies the mantle .

Notes

The crust includes the continents and the ocean bottom and is generally estimated to be about five to twenty-five miles thick.

The crust is made from relatively lightweight rocks that floated to the surface when the Earth was molten early in its history.

Other Words From

• crust·less adjective
• in·ter·crust verb (used with object)
• un·der·crust noun

Word History and Origins

Origin of crust¹

First recorded in 1275–1325; Middle English, from Anglo-French, Old French cruste, croste, from Latin crusta “hard coating, crust”

Word History and Origins

Origin of crust¹

C14: from Latin crūsta hard surface, rind, shell

Idioms and Phrases

see upper crust .

Example Sentences

The event at Dickson Fjord, Dr Hicks added, “is the perhaps first time a climate change event has impacted the crust beneath our feet all the world over.”

From BBC

The fiction writer Alan Furst, in Mission to Paris, writing of the political upper crust of France in the autumn of 1938, could have been describing America’s elite in 2024:

From Salon

As glacial ice melts, the downward pressure on Earth’s thin outer crust eases, causing the ground to rebound.

From Salon

Our planet’s crust has a band of ancient craters that formed around 465 million years ago.

From Slate

That moon is almost entirely covered by a vast ocean underneath a crust of ice.

From Salon

Related Words

• layer
• skin
• surface