Definition of "septum" [‖Sep•tum]

• A thin partition or membrane that divides two cavities or soft masses of tissue in an organism: the nasal septum; the atrial septum of the heart. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "But a drop-pearl hanging to the septum is at least as pretty as the heavy pendants by which some European women lengthen their ears."
• "A tiny pit on each side of the septum is lined with nonfunctioning chemoreceptors."
• "I'm prone to ear infections of the supa-special nasty kind, and they often come hand-in-hand (or cochlea in septum, or whatever) with sinus infections."