1. n. A register inside a processor used as both one operand of, and the destination for, arithmetic and logical operations. Generally used to designate the only register on a rocessor that holds the result of an arithmetic or logical operation. The 8085 is a single-accumulator machine since essentially all math and logic happens with and to register A. The 68000 can do math on any general-purpose register, so one rarely speaks of it as having an ccumulator. 2. n. The register, which can be a real register or a data structure in memory, that is used as one argument of, and the destination for, floating-point operations. Abbreviated FPA Floating-Point Accumulator).