crust

noun

ˈkrəst 

1

a

: the hardened exterior or surface part of bread

b

: a piece of this or of bread grown dry or hard

2

a

: the pastry shell of a pie : piecrust

b

: the bready layer that forms the foundation of a pizza

3

: a hard or brittle external coat or covering: such as

a

: a hard surface layer (as of soil or snow)

b

: the outer part of a planet, moon, or asteroid composed essentially of crystalline rocks

c

: a deposit built up on the interior surface of a wine bottle during long aging

d

: an encrusting deposit (as of the eye) of dried secretions or exudate

also : scab

4

: gall, nerve

crust verb

crustal

ˈkrə-stᵊl 

adjective

crustless

ˈkrəs(t)-ləs 

adjective

Synonyms

• nerve
• gall
• arrogance
• sauce

Examples of crust in a Sentence

Her children prefer to eat their sandwiches with the crust cut off.

a pie with flaky crust

He likes pizza with thin crust.

Recent Examples on the Web

Geologists have long suspected that Afar is underlain by a mantle plume, a pillar of upwelling hot material that is helping to drive apart the overlying crust. —Ian Randall, MSNBC Newsweek, 25 June 2025

The distinction between being unique and ho hum is as thin as the crust. —Bill Field, Hartford Courant, 19 June 2025

Her thesis work on biological soil crust restoration was published in January 2023. —The San Diego Union Tribune, San Diego Union-Tribune, 14 June 2025

Utah’s Canyonlands National Park also depends on cairns to help hikers through its terrain and off the delicate biological soil crust. —Addy Bink, The Hill, 14 June 2025

Word History

Etymology

Middle English crouste, cruste, borrowed from Anglo-French & Latin; Anglo-French cruste, crouste, going back to Latin crusta "hard coating or surface layer, shell of an arthropod or crustacean, mineral flake, stone slab used in paneling," perhaps, if going back to *krus-to- "something crushed or pounded into a hard layer," from a zero-grade nominal derivative of Indo-European *kreu̯s- "beat, crush, pound," whence also Old English hruse "earth, ground," Old High German roso, rosa "crust, layer of ice" (going back to Germanic *hrusōn-) — more at anacrusis

Note: The hypothetical base *krus-to- is suggested by Michiel de Vaan, Etymological Dictionary of Latin and the Other Italic Languages (Leiden: Brill, 2008), p. 147, though the older handbooks (Walde-Hoffman, Ernout-Meillet) tend to support a connection with Greek krýos "icy cold, frost" and other derivatives, going back to a presumed homonymous *krus- (see cryo-). As de Vaan points out, however, Latin crusta does not mean "ice." The original sense of the Germanic noun *hrusōn- is not certain. Greek krýstallos "ice, rock crystal" is almost certainly unrelated (see crystal entry 1).

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing crust

• earn a/one's crust
• the upper crust
• upper crust

Rhymes for crust

• bused
• bust
• cussed
• dust
• fussed
• fust
• gust
• just
• lust
• mussed
• must
• rust

Kids Definition

crust

noun

ˈkrəst 

1

a

: the hardened outside surface of bread

b

: a piece of dry hard bread

2

: the pastry cover of a pie

3

a

: a hard surface layer

a crust of snow

b

: the outer part of the earth

crustal

ˈkrəs-təl 

adjective

Medical Definition

crust

noun

ˈkrəst 

1

: scab sense 2

2

: an encrusting deposit of serum, cellular debris, and bacteria present over or about lesions in some skin diseases (as impetigo or eczema)

crust verb