A small sac, pouch, or cyst.
The smaller of the two fluid-filled sacs forming part of the labyrinth of the inner ear (the other being the utricle). It contains a region of hair cells and otoliths which send signals to the brain concerning the orientation of the head.
A bladder, especially the urinary bladder or the gall bladder.
The vesica piscis or oval aureole in mediaeval painting.