A little sac, or bag; a utricle; especially, a part of the membranous labyrinth of the ear. See the Note under Ear.

One of the maculae, vaguely sac-like areas of the vestibular apparatus in the inner ear involved in the perception of linear acceleration, orientation in a gravity field, and low-frequency or high-volume sounds. See The Ear.

a small pouch into which the semicircular canals open