a person who is employed to collect payments (as for rent or taxes)
a voltaic battery that stores electric charge
(computer science) a register that has a built-in adder that adds an input number to the contents of the register
One who, or that which, accumulates.
The word accumulator comes from the Latin accumulātor, which is an agent noun derived from accumulō meaning "to pile up." It originally referred to something that gathers or accumulates items together.