Other forms: crusts
The crust is the thin solid outer layer of the earth. The earth's crust, oceanic crust, crust and mantle.
It is astonishingly thin in proportion — about five kilometres under the oceans and forty under the continents, on a planet six thousand kilometres to the centre. Oceanic crust is younger because it is constantly made and swallowed. The word also names the outside of a loaf.
1nouncrustThe thin solid outer layer of the earth.
“The earth's crust is thinner under the oceans than under the continents.”
2nounhardThe hard outside of a loaf.
“My son won't eat the crust, so I cut it off his sandwiches.”
crust is an outer layer.
Latin crusta means a hard outer covering, from a root meaning to form a crust. Crustacean comes from the same shell.
Middle English
cruste
English, today
crust
Built from
From Middle English cruste. From Middle English cruste, from Anglo-Norman - and Old French cruste, from Latin crusta (“hard outer covering”), from Proto-Indo-European krustós (“hardened”), from krews- (“to form a crust, begin to freeze”), related to Old Norse hroðr (“scurf”), Old English hruse (“earth”), Old High German hrosa (“crust, ice”), Latvian kruvesis (“frozen mud”), Ancient Greek κρύος (“frost, icy cold”), κρύσταλλος (“crystal, ice”), ae 𐬑𐬭𐬎𐬰𐬛𐬭𐬀- (“hard”), Sanskrit क्रूड् (“thicken, make hard”). a doublet of crusta.
Etymology from Wiktionary, CC BY-SA