VESICLE

noun Etymology: Middle French vesicule, from Latin vesicula small bladder, blister, from diminutive of vesica Date: 1578 1. a membranous and usually fluid-filled pouch (as a cyst, vacuole, or cell) in a plant or animal, a small abnormal elevation of the outer layer of skin enclosing a watery liquid ; blister , a pocket of embryonic tissue that is the beginning of an organ, a small cavity in a mineral or rock