You Say “Vestibule . . . !”
But there are so many other words that could be used instead.
\ ves-tuh-byool \, noun;
According to http://www.dictionary.com, a vestibule is defined as:
1. a passage, hall, or antechamber between the outer door and the interior parts of a house or building.
2. Railroads. an enclosed space at the end of a passenger car, serving as a sheltered entrance to the car from another car or from outside the train.
3. Anatomy, Zoology. any of various cavities or hollows regarded as forming an approach or entrance to another cavity or space, as that of the internal ear.
But according to my copy of The Highly Selective Thesaurus for the Extraordinarily Literate, here are some other options to help extend your vocabulary (depending on your specific need or usage):
Source: The Highly Selective Thesaurus for the Extraordinarily Literate by Eugene Ehrlich.
Tags: Eugene Ehrlich, Synonyms, The Highly Selective Thesaurus for the Extraordinarily Literate, Thesaurus, Vestibule