vestibuli

Vestibuli is a Latin form associated with the noun vestibulum, most often encountered in scholarly Latin phrases. In modern English, the corresponding term is typically vestibule in the singular and vestibula or vestibulae in Latin plurals. As a standalone English noun, vestibuli is uncommon and usually appears only in Latinized contexts or in references to Latin grammar.

In anatomy, vestibule refers to several cavity regions. The vestibule of the inner ear is the central part of the bony labyrinth that interfaces with the cochlea and the semicircular canals; it contains the utricle and saccule and plays a key role in balance and spatial orientation. The nasal vestibule is the anterior portion of the nasal cavity just inside the nostrils, lined by skin with vibrissae (nasal hairs) that help filter inhaled air. The oral vestibule is the space between the lips and cheeks and the teeth, separating the oral cavity proper from the outside environment and aiding in the initial phase of mastication.

In architecture, a vestibule is an antechamber or lobby area adjacent to an exterior door. It serves as a transitional space that helps regulate temperature and provides a holding area before entering the main interior.

Etymology notes: vestibulum means “entryway” or “place of approach” in Latin, with vestibuli as the genitive singular form and vestibula as the standard Latin plural.