1. A small blister
2. Bubble; also; a small particle
3. Something esembling a bleb; especially; a vesicular outgrowth of a plasma or nuclear membrane

ETYM Latin vesicula, dim. of vesica a bladder, blister; akin to Skr. vasti bladder: cf. French vésicule.
A small anatomically normal sac or bladderlike structure (especially one containing fluid); SYN. cyst.
Small blister; bladderlike or rounded cavity; cell; cyst.