Vesicle /(?)/

Ves·i·cle

Vesicle

n.
  1. A bladderlike vessel; a membranous cavity; a cyst; a cell.
  2. A small bladderlike body in the substance of a vegetable, or upon the surface of a leaf. (Bot.)
  3. A small, and more or less circular, elevation of the cuticle, containing a clear watery fluid. (Med.)
  4. A cavity or sac, especially one filled with fluid; as, the umbilical vesicle. (Anat.)
  5. A small convex hollow prominence on the surface of a shell or a coral. (Zool.)
  6. A small cavity, nearly spherical in form, and usually of the size of a pea or smaller, such as are common in some volcanic rocks. They are produced by the liberation of watery vapor in the molten mass. (Geol.)