Meaning of “inside” - Learner’s Dictionary

inside

noun us uk /ˌɪnˈsaɪd/
Extra Examples
You ought to see the inside of the house.The fries were crispy on the outside and fluffy on the inside.The inside of the bowl was dirty.His name was on the inside of his jacket.They're decorating the inside of the building.
the inside

B2 the part of something that is under its surface:

I cleaned the inside of the oven.
The door had been locked from the inside.
inside out

B2 If a piece of clothing is inside out, the part that is usually outside is on the inside:

Harry, you've got your sweater on inside out again.

(Definition of “inside noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)