Meaning of “outside” - Learner’s Dictionary

outside

preposition us uk /ˌaʊtˈsaɪd/ also US outside of
NEAR

A2 not in a particular building or room, but near it:

She waited outside his room for nearly two hours.

More examples

NOT IN

A2 not in:

a town just outside Munich
You have to phone a different number outside office hours.

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