[noun] [C] [formal] - a room just inside the outer door of a public building, which you go through in order to reach the other rooms of the building; foyerVisitors are asked to leave their umbrellas in the vestibule.I'll wait for you in the vestibule.(US) A vestibule is also a small enclosed area on the front of a house; a porch.
VESTIBULE
Meaning of VESTIBULE in English
Cambridge English vocab. Кембриджский английский словарь. 2012