e/Sinus ostium

Information
has gloss	eng: A sinus ostium (plural: sinus ostia) is the opening that connects a sinus to the nasal cavity itself. It is a tight area that tends to have a higher percentage of cilia than the surrounding mucosa.
lexicalization	eng: sinus ostium
instance of	(noun) the upper part of the human body or the front part of the body in animals; contains the face and brains; "he stuck his head out the window" head, caput