From Longman Dictionary of Contemporary Englishcrustcrust /krʌst/ ●●○ noun [countable, uncountable] 1 the hard brown outer surface of bread sandwiches with the crusts cut off2 DFthe baked outer part of foods such as pies or pizzas a thin-crust pizza3 SURFACEa thin hard dry layer on the surface of something A hard gray crust had formed on the bottom of the tea kettle.4 the hard outer layer of the Earth deep within the Earth’s crust → earn a crust at earn(1), upper crust
Examples from the Corpus
crust• a pizza with a thin, crispy crust• We were barely twenty when we got married, back before the Earth's crust cooled.• the Earth's crust• The extra rises will affect the crust, texture, and flavor, usually giving a crustier, slightly more sour loaf.• The thickness of the crust, for example, varies widely between continents and oceans.• Use the sharp knife to cut off the crusts.• The heat sets the crust and quickly evaporates the surface moisture, crisping the crust.• It was a nightmare of a trip, the trucks constantly breaking through the crust and having to be dug out.• Jimmy only eats sandwiches with the crusts cut off.crust ... formed• They ran the cell all day, after which time a green crust had formed on the cathode.Origin crust (1300-1400) Latin crusta “crust, shell” 