septum

n. a thin wall of bone or tissue that separates two cavities in the body, such as the nostrils in the nose.

n. a partition separating two cavities or masses of softer tissue in an organism, most frequently the nasal septum.

“He had surgery to fix a deviated septum that made it hard for him to breathe.”

“The surgeon corrected the deviated nasal septum to improve the patient's airflow and resolve chronic sinus infections.”

Technical

n. a type of jewelry or piercing that goes through the wall between your nostrils.

n. a colloquial reference to a septum piercing or the jewelry worn within the nasal partition.

“She decided to get a small silver ring for her new septum piercing.”

“The popularity of the septum as a site for body modification has grown significantly within urban subcultures over the last decade.”

Informal