Exemple:
In order to make a fried egg, you must first break the shell of the egg and then put what's inside into a frying pan. 
Davide Restivo
Licence photo:
CC: Attribution, Commercial Use
Regionalism:
Neutral
Regional variant:
Neutral
Full Expression:
The “sh” Sound ( /ʃ/ ): shell
the hard outer covering of something, such as that of an oyster in the ocean which must be forced open in order for the mollusc inside to be eaten