crust

1. (British, Australia, New Zealand, Ireland, Canada, Northern US) A slice of bread cut from the end of a loaf; the heel.AustraliaBritishCanadaIrelandNew-ZealandNorthern-UScountableuncountable

2. (geology) The outermost layer of the lithosphere of the Earth.Examples: "The crust (a mere 1% of the Earth's volume) is made of lighter melt products from the mantle."countableuncountable

3. (astronomy, by extension) The outermost layer of any terrestrial planet.broadlycountableuncountable

4. (British, Australia, informal) A living.Examples: "to earn one's crust"; "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."Synonyms: daily bread, income, livelihoodAustraliaBritishcountableinformaluncountable

5. (uncountable, informal) Nerve, gall.Examples: "You've got a lot of crust standing there saying that."; "“Oh?” she said. “So you have decided to revise my guest list for me? You have the nerve, the – the –” I saw she needed helping out. “Audacity,” I said, throwing her the line. “The audacity to dictate to me who I shall have in my house.” It should have been “whom”, but I let it go. “You have the –” “Crust.” “– the immortal rind,” she amended, and I had to admit it was stronger, “to tell me whom” – she got it right that time – “I may entertain at Brinkley Court and who” – wrong again – “I may not.”"informaluncountable

6. (UK, Australia, slang, dated) The head.Examples: "“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.”"AustraliaUKcountabledatedslanguncountable