vestibule

Vestibule, from the Latin vestibulum meaning forecourt or entrance, is a term used in architecture to describe a small lobby or antechamber that provides an entryway between the exterior and main interior spaces. In building design it acts as a transitional zone that can help control weather, acoustics, and privacy, and it may contain doors to multiple rooms or to the exterior.

In architectural contexts, vestibules are common in churches, train stations, and public buildings where a defined threshold helps manage movement and climate before entering more occupied areas. They may vary in size from simple entry alcoves to more substantial rooms with seating or display areas, and they are often designed to contribute to the building's overall style and flow.

In anatomy the term denotes a cavity or chamber at the entrance of a canal or body region. Examples include the nasal vestibule, the oral vestibule, and the vestibule of the inner ear. The nasal vestibule lies just inside the nostrils and is lined with skin bearing hairs that filter large particles. The oral vestibule is the space between the lips and cheeks and the teeth and gums. The vestibule of the inner ear is a central chamber within the bony labyrinth that connects the cochlea with the semicircular canals and contains the utricle and saccule, contributing to balance and spatial orientation.

Overall, vestibule describes a transitional space serving entry, separation, and initial processing in both built environments and bodily systems.