http://en.wikipedia.org/wiki/Vestibule

Architecture
Main article: Vestibule (architecture)
a large entrance
a lobby, entrance hall, or passage between the outer door and the interior of a building
an enclosed area between two rail cars
a reception area
a footstool
a toilet
a bar-stool
an antechamber
an entry room
a laundry chute in an American apartment building
a passageway acting as an airlock between two environments
Also known as a mud room in the american home association.
Related:

a covered section between the outer opening and inner opening of a tent, typically used for the storage of boots, packs and small equipment.
a sleeveless item of clothing from 17th century France made from woven string, often worn when 'beating wifes'.
[edit] Other
The Vestibules (formerly known as Radio Free Vestibule), a Canadian comedy troupe
Teh Vestibule, an IGN message board
Vestibulum (wasp), a wasp genus
The Vestibule of Hell is the first layer in the Divine Comedy.
Articulated bus