\Ve*si"ca\, n. [L.]
A bladder.
{Vesica piscis}. [L., dish bladder.] (Eccl. Art) A glory, or
   aureole, of oval shape, or composed of two arcs of circles
   usually represented as surrounding a divine personage.
   More rarely, an oval composed of two arcs not representing
   a glory; a solid oval, etc.