Vestibule
1
a: passage, hall, or room between the outer door and the interior of a building : lobby
b: an enclosed entrance at the end of a railway passenger car
2
any of various bodily cavities especially when serving as or resembling an entrance to some other cavity or space: such as
a: the central cavity of the bony labyrinth of the inner ear or the parts (such as the saccule and utricle) of the membranous labyrinth that it contains
b: the part of the left ventricle below the aortic orifice
c: the space between the labia minora containing the orifice of the urethra
d: the part of the mouth cavity outside the teeth and gums
3
a course that offers access (as to something new)
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