What is "nasal meatus"

n. the passages in the nasal cavity formed by the projections of the nasal conchae

A nasal meatus is a nasal passage of the nasal cavity, of which there are three; the superior meatus, middle meatus and inferior meatus. These nasal meatuses are also known as meatus nasi superior, meatus nasi medius, and meatus nasi inferior. (A meatus is a passage or opening in the body, especially one which is open to the exterior).

The nasal meatuses are located beneath each of the corresponding nasal conchae. In the case where a fourth, supreme nasal concha is present, there is a fourth supreme nasal meatus.