crust /kɹʌst/noun 12verb 2forms 3phrases 3 noun12 •A more solid, dense or hard layer on a surface or boundary. •The external, hardened layer of certain foodstuffs, including most types of bread, fried meat, etc. •An outer layer composed of pastryTh' impenetrable crust thy teeth defies. — 1693 •The outermost layer of the lithosphere of the Earth.The crust (a mere 1% of the Earth's volume) is made of lighter melt products from the mantle. — 2012 •The outermost layer of the lithosphere of any terrestrial planet. •The shell of crabs, lobsters, etc. •The bread-like base of a pizza. •(UK, Australia) A slice of bread cut from the end of a loaf; the heel. •(UK, informal) A living.Like most of us, I am frequently asked by friends and people I meet in business situations or round the dinner table what I do to earn my crust. — 1999 •(informal) Nerve, gall.You've got a lot of crust standing there saying that. •Ellipsis of crust punk, a subgenre of punk music. •(slang, old-fashioned) The head.“Well, all I can say is that if yer don't take yer dial outer the road I'll bloomin' well take an' bounce a gibber off yer crust.” — 1918 verb2 •To cover with a crust.The whole body is crusted over with ice. — 1662 •To form a crust., The Goblin Reign Boxed Set Thistle held her hand over the wound and pressed a wad of tree moss against it. "Don't move," she said. "Let it crust." formscrusted · crusting · crusts Phrases with crust crack a crustTo make a living. earn one's crustTo earn money, to do something as a job. upper-crustPosh, upper-class; pertaining to the upper crust.