The definition of crust is the hard, outer part of a loaf of bread, or a layer of pastry covering a pie, or a hardened layer on something.(noun)
Crust is defined as forming a hard outer layer.(verb)
When the ice freezes over a lake, this is an example of when it crusts.
See crust in Webster's New World College Dictionary
Origin: ME cruste < OFr or L: OFr crouste < L crusta: for IE base see crude
transitive verb, intransitive verb
See crust in American Heritage Dictionary 4
Origin: Middle English cruste, from Old French crouste, from Latin crūsta; see kreus- in Indo-European roots.
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