proprioception[prō′prē ə sep′s̸hən]
Used by arrangement with John Wiley & Sons, Inc.
(countable and uncountable, plural proprioceptions)
From Latin proprius (“one's own").
In other words, what is sometimes referred to as "sixth sense" in medicine--if you close your eyes, you can still describe if you're sitting or standing, and how your legs or arms are positioned. That's proprioception.