Definition of crusts:
(n) :
The external, hardened layer of certain foodstuffs, including most types of bread, fried meat, etc.
(n) :
An outer layer composed of pastry
(n) :
The bread-like base of a pizza.
(n) :
A more solid, dense or hard layer on a surface or boundary.
(n) :
(British, Australia, New Zealand, Ireland, Canada, Northern US) A slice of bread cut from the end of a loaf; the heel.
(n) :
The shell of crabs, lobsters, etc.