A vestibule is a small room or passage that serves as an entrance or antechamber between the outer door and the interior of a building). It can be used for various purposes such as waiting, reducing heat loss, providing storage space for outdoor clothing, etc. ). The term applies to structures in both modern and classical architecture since ancient times). In modern architecture, a vestibule is typically a small room next to the outer door and connecting it with the interior of the building). In ancient Roman architecture, a vestibule was a partially enclosed area between the interior of the house and the street).

Apart from architecture, the term vestibule is also used in other fields such as anatomy, biology, and medicine. In general, vestibule refers to a small space or cavity at the beginning of a canal. For example, the vestibule of the ear is the central part of the inner ear labyrinth, which contains the vestibular system that helps maintain balance and spatial orientation. The vulval vestibule is a part of the vulva between the labia minora into which the urinary meatus (urethral opening) and the vaginal opening open. The nasal vestibule is the nostrils, simply lined with an extension of skin epithelium, in contrast to the nasal cavity, which is lined with respiratory epithelium. The vestibule of the mouth is the space between the lips (or cheek) and teeth. The vestibule of the larynx is between the epiglottis and rima glottidis. The aortic vestibule is the part of the left ventricle of the heart just below the aortic valve.

In summary, a vestibule is a small room or passage that serves as an entrance or antechamber between the outer door and the interior of a building. It can also refer to a small space or cavity at the beginning of a canal in anatomy, biology, and medicine.