Computer Dictionary of Information Technology

floating-point accelerator

(FPA) Additional hardware to perform functions on floating point numbers such as addition, multiplication, logarithms, exponentials, trigonometric functions and various kinds of rounding and error detection. A floating point accelerator often functions as a co-processor to the CPU.

The term "floating-point accelerator" suggests a physically larger system, often an extra circuit board, whereas a "floating-point unit" is probably a single chip or even part of a chip.