crusts is a form of:

Crust



noun
1.
(The hard outer layer of something, especially bread; the pastry covering of a pie, any hard surface layer, an insolence, the solid surface layer, the solid outer shell of the earth) bread crust សំបកក្រៀមៗ (នំប៉័ង) / earth's crust ស្រទាប់លើ
verbpast tense: crusted ; past participle: crusted ; present participle: crusting ;
1.
(INTRANSITIVE) (To cover or become covered with a crust, to form a crust) ឡើងក្រៀមពីក្រៅ
Example: An icy crust on the snow; the crust of the earth, Freezing rain crusted the sonw.
2.
(TRANSITIVE) ធ្វើឱ្យក្រៀមពីក្រៅ
  • the upper crust
    - វណ្ណៈខ្ពស់បំផុតក្នុងសង្គម
  • upper crust
    - មនុស្សមានវណ្ណៈជាន់ខ្ពស់
ENGLISH MEANING
noun
1.
The cover or case of a pie, in distinction from the soft contents.
2.
The hard external coat or covering of anything; the hard exterior surface or outer shell; an incrustation; as, a crust of snow.
3.
The hard exterior or surface of bread, in distinction from the soft part or crumb; or a piece of bread grown dry or hard.
4.
The dough, or mass of doughy paste, cooked with a potpie; -- also called dumpling.
5.
The exterior portion of the earth, formerly universally supposed to inclose a molten interior.
6.
The shell of crabs, lobsters, etc.
7.
A hard mass, made up of dried secretions blood, or pus, occurring upon the surface of the body.
8.
An incrustation on the interior of wine bottles, the result of the ripening of the wine; a deposit of tartar, etc.
verbpast tense: crusted ; past participle: crusted ; present participle: crusting ;
1.
To cover with a crust; to cover or line with an incrustation; to incrust.
2.
(INTRANSITIVE) To gather or contract into a hard crust; to become incrusted.