Vesicle

1. A bubble within the cell which is surrounded by cell membrane material and is formed by pinching off part of the cell membrane. Vesicles contain particles which the cell is importing (endocytosis), or waste products and secretions which the cell is exporting (exocytosis).
   
   
2. A small (less than one centimeter in diameter), fluid-filled skin lesion, usually raised; a blister.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.

Ves"i*cle (?), n. [L. vesicula, dim. of vesica a bladder, blister; akin to Skr. vasti bladder: cf. F. v'esicule.]

A bladderlike vessel; a membranous cavity; a cyst; a cell.

(a) Bot.

A small bladderlike body in the substance of vegetable, or upon the surface of a leaf.

(b) Med.

A small, and more or less circular, elevation of the cuticle, containing a clear watery fluid.

(c) Anat.

A cavity or sac, especially one filled with fluid; as, the umbilical vesicle.

(d) Zool.

A small convex hollow prominence on the surface of a shell or a coral.

(e) Geol.

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.

© Webster 1913.