Meaning

noun the outer layer of the Earth

noun a hard outer layer that covers something

noun the trait of being rude and impertinent; inclined to take liberties

originFrom 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 (krúos, “frost, icy cold”),…

Etymology from Wiktionary, CC BY-SA 3.0