crust

Etymology

It is inherited from Middle English cruste, also crouste,^[2][3][4] borrowed from Old French crouste, modern croûte,^[5][6][3][7] with the Anglo-Norman form cruste from about 1240,^[8][2] or in some senses directly borrowed from Latin crusta (“rind, crust, shell, bark”).^[6][5][9] The OED notes that bread crust is the earliest popular sense in French, but that medical writers used the word for a scab after Latin at an early date.^[6] Etymonline traces the Latin word to Proto-Indo-European *krus-to- (“that which has been hardened”), a suffixed form of *kreus- (“to begin to freeze, form a crust”);^[5][10][9] Merriam-Webster's Unabridged is more cautious.^[2] Klein and Hoad compare Ancient Greek κρύος (krúos, “icy cold, frost”) and κρύσταλλος (krústallos, “ice, crystal”), the source of crystal, Old High German hrosa (“crust, ice”), Old English hrūse (“earth, ground”) and Latin crūdus (“raw”), the source of crude.^[7][3] The verb is from the noun, after Old French crouster and Latin crustāre.^[6][9][2]

Earliest recorded meaning

The hard outer part of a loaf or roll of bread: about 1325, in a political song, and before 1330 in Otuel;^[6] Barnhart dates it probably before 1325, and Etymonline to the early 14th century.^[9][5]

Semantic evolution

From bread the word spread, after Latin, to other hard outer layers: a scab on the skin (1398, in Trevisa), a hard coating or deposit on anything (about 1529), the pastry of a pie (1598) and the shell of an animal or plant (1615).^[6][5] The geological sense, the outer layer of the earth, is first recorded in 1555.^[6][9][5] A figurative outer shell, hard to get through or only superficial, is from 1651,^[6] and a crust of bread as a meagre living gave the slang pick up a crust or earn a crust, to work for a living, recorded from 1812;^[11] the OED's record of crust "a livelihood" is Australian, from 1916.^[6][12] American slang used crust for nerve or cheek from 1900.^[11] The verb is first intransitive, "to form a crust" (about 1430), and transitive, "to cover with a crust", from 1545.^[6][5] Ayto notes that a custard was originally a kind of pie in a crust.^[4]

Timeline

• c. 1325 – the hard outer part of bread.^[6]
• 1398 – a scab.^[6]
• c. 1430 – verb, to form a crust.^[6]
• c. 1529 – a hard coating or deposit.^[6]
• 1545 – verb, to cover with a crust.^[6][5]
• 1555 – the outer layer of the earth.^[6][9]
• 1598 – the pastry of a pie.^[6]
• 1615 – the shell of an animal or plant.^[6]
• 1812 – slang, a living (pick up a crust).^[11]
• 1900 – US slang, nerve, cheek.^[11]

Modern meaning

Noun

1. The hard outer part of bread, or a piece of bread that is mostly this: He fed the crusts to the ducks.
2. The baked pastry shell of a pie or tart.
3. Any hard outer layer or coating: a crust of frozen snow.
4. (geology) The solid outer layer of the earth, above the mantle.
5. A scab on the skin.
6. (informal, chiefly Australian and New Zealand) A livelihood: earn a crust.
7. (slang) Nerve, cheek.

Verb

1. To form a crust, or become covered with one: The mud crusted as it dried.
2. To cover something with a crust.

Word family

• crustless
• crustal
• undercrust
• crusted
• upper crust

Related words

• custard
• croustade
• crouton
• crusty
• encrust
• crustacean
• crystal
• crude

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ a b c Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
4. ^ a b Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
5. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
7. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
9. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
11. ^ a b c d Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com
12. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press