What does Accumulator mean?
As a type of traditional register, an accumulator is a design within a CPU core that holds “intermediate” results. While a computer or device is working on multi-step operations, intermediate values are sent to the accumulator and then overwritten as needed.
Techopedia explains Accumulator
In early computing, the function of the accumulator as a temporary way to hold intermediate values for lower processing needs was fairly integral. The ENIAC, for example, had over a dozen accumulators built in. As cores progressed, the accumulator became fairly obsolete both in semantic identity and design: Newer computing architectures more often reference a general register, and with multi-core design builds, the “accumulator” as a referenced object is mainly a thing of the past.