Meaning of “outside” - Learner’s Dictionary

outside

preposition us uk /ˌaʊtˈsaɪd/ also US outside of
Armed police stood guard outside the house.A gang of youths were loitering outside the cinema.The two leaders posed for photographs outside the White House.A car pulled up outside the bank and two men got out.A crowd of well-wishers gathered outside the hospital.
NEAR

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

She waited outside his room for nearly two hours.
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)