(1):
(n.) An apparatus by means of which energy or power can be stored, such as the cylinder or tank for storing water for hydraulic elevators, the secondary or storage battery used for accumulating the energy of electrical charges, etc.
(2):
(n.) A system of elastic springs for relieving the strain upon a rope, as in deep-sea dredging.
(3):
(n.) One who, or that which, accumulates, collects, or amasses.