Vestibule

n. entrance hall just inside the front doors of a building; small cavity leading from one larger cavity or canal to another (Anatomy); closed passageway between two railroad cars

Vestibule can have the following meanings, each primarily based upon a common origin, from early 17th century French, derived from Latin vestibulum, -i n. ‘entrance court.’
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Vestibule /ves·ti·bule/ a space or cavity at the entrance to a canal.vestib´ular vestibule of aorta a small space at root of the aorta. [more]Vestibule - Community and Resources

Noun
1. a large entrance or reception room or area
(synonym) anteroom, antechamber, entrance hall, hall, foyer, lobby
(hypernym) room
(hyponym) narthex
(part-holonym) building, edifice
2. any of various bodily cavities leading to another cavity (as of the ear or vagina)
(hypernym) cavity, bodily cavity, cavum
(hyponym) vestibule of the ear

n. hall, vestibule, entrance; foyer, antechamber, anteroom; small cavity leading from one larger cavity or canal to another (Anatomy)